Saturday, May 11

Common Logarithm Table


A numerical expressipon may involve multiplication, division, or exponents of large numbers. In all such calculations, the log tables prove to be an effective tool in simplyfying the complicated computations. Before seeing the common logarithm table, let us learn what characteristic and mantissa is.

In general, the logarithm of any number "n" can be expresed as follows:
log n = p + log m, where p is an integer and 1 ≤ m < 10.
"p" is the integral of log n, is defined as the characteristic and th elog m is defined as mantissa.
Since log 1 = 0 and log 10 = 1 and 1 ≤ m < 10, we have log m as a decimal.
Note: The charcteristic of a number greater than 1 is one less than the number of digits in its integral part.

Ex: Charcteristic of 36177 is 4
Total number of digits = 5, one less than 5 is 4.
Consider log 36.122
We have only two digits in the integral part. So, characteristic of 36.122 is 1.

Common logarithm table from 1 to 4.99


101.10.04139272.10.32221933.10.49136174.10.6127839
1.0010.00043411.110.0453232.110.32428253.110.49276044.110.6138418
1.0020.00086771.120.0492182.120.32633593.120.49415464.120.6148972
1.0030.00130091.130.05307842.130.32837963.130.49554434.130.6159501
1.0040.00173371.140.05690492.140.33041383.140.49692964.140.6170003
1.0050.00216611.150.06069782.150.33243853.150.49831064.150.6180481
1.0060.0025981.160.0644582.160.33445383.160.49968714.160.6190933
1.0070.00302951.170.06818592.170.33645973.170.50105934.170.6201361
1.0080.00346051.180.0718822.180.33845653.180.50242714.180.6211763
1.0090.00389121.190.0755472.190.34044413.190.50379074.190.622214
1.010.00432141.20.07918122.20.34242273.20.505154.20.6232493
1.0110.00475121.210.08278542.210.34439233.210.5065054.210.6242821
1.0120.00518051.220.08635982.220.3463533.220.50785594.220.6253125
1.0130.00560951.230.08990512.230.34830493.230.50920254.230.6263404
1.0140.0060381.240.09342172.240.3502483.240.5105454.240.6273659
1.0150.0064661.250.096912.250.35218253.250.51188344.250.6283889
1.0160.00689371.260.10037052.260.35410843.260.51321764.260.6294096
1.0170.0073211.270.10380372.270.35602593.270.51454784.270.6304279
1.0180.00774781.280.107212.280.35793483.280.51587384.280.6314438
1.0190.00817421.290.11058972.290.35983553.290.51719594.290.6324573
1.020.00860021.30.11394342.30.36172783.30.51851394.30.6334685
1.0210.00902571.310.11727132.310.3636123.310.5198284.310.6344773
1.0220.00945091.320.12057392.320.3654883.320.52113814.320.6354837
1.0230.00987561.330.12385162.330.36735593.330.52244424.330.6364879
1.0240.01031.340.12710482.340.36921593.340.52374654.340.6374897
1.0250.01072391.350.13033382.350.37106793.350.52504484.350.6384893
1.0260.01114741.360.13353892.360.3729123.360.52633934.360.6394865
1.0270.01157041.370.13672062.370.37474833.370.52762994.370.6404814
1.0280.01199311.380.13987912.380.3765773.380.52891674.380.6414741
1.0290.01241541.390.14301482.390.37839793.390.53019974.390.6424645
1.030.01283721.40.1461282.40.38021123.40.53147894.40.6434527
1.0310.01325871.410.14921912.410.3820173.410.53275444.410.6444386
1.0320.01367971.420.15228832.420.38381543.420.53402614.420.6454223
1.0330.01410031.430.1553362.430.38560633.430.53529414.430.6464037
1.0340.01452051.440.15836252.440.38738983.440.53655844.440.647383
1.0350.01494041.450.1613682.450.38916613.450.53781914.450.64836
1.0360.01535981.460.16435292.460.39093513.460.53907614.460.6493349
1.0370.01577881.470.16731732.470.3926973.470.54032954.470.6503075
1.0380.01619741.480.17026172.480.39445173.480.54157924.480.651278
1.0390.01661561.490.17318632.490.39619933.490.54282544.490.6522463
1.040.01703331.50.17609132.50.397943.50.5440684.50.6532125
1.0410.01745071.510.17897692.510.39967373.510.54530714.510.6541765
1.0420.01786771.520.18184362.520.40140053.520.54654274.520.6551384
1.0430.01828431.530.18469142.530.40312053.530.54777474.530.6560982
1.0440.01870051.540.18752072.540.40483373.540.54900334.540.6570559
1.0450.01911631.550.19033172.550.40654023.550.55022844.550.6580114
1.0460.01953171.560.19312462.560.408243.560.551454.560.6589648
1.0470.01994671.570.19589972.570.40993313.570.55266824.570.6599162
1.0480.02036131.580.19865712.580.41161973.580.5538834.580.6608655
1.0490.02077551.590.20139712.590.41329983.590.55509444.590.6618127
1.050.02118931.60.204122.60.41497333.60.55630254.60.6627578
1.0510.02160271.610.20682592.610.41664053.610.55750724.610.6637009
1.0520.02201571.620.2095152.620.41830133.620.55870864.620.664642
1.0530.02242841.630.21218762.630.41995573.630.55990664.630.665581
1.0540.02284061.640.21484382.640.42160393.640.56110144.640.666518
1.0550.02325251.650.21748392.650.42324593.650.56229294.650.667453
1.0560.02366391.660.22010812.660.42488163.660.56348114.660.6683859
1.0570.0240751.670.22271652.670.42651133.670.56466614.670.6693169
1.0580.02448571.680.22530932.680.42813483.680.56584784.680.6702459
1.0590.0248961.690.22788672.690.42975233.690.56702644.690.6711728
1.060.02530591.70.23044892.70.43136383.70.56820174.70.6720979
1.0610.02571541.710.23299612.710.43296933.710.56937394.710.6730209
1.0620.02612451.720.23552842.720.43456893.720.57054294.720.673942
1.0630.02653331.730.23804612.730.43616263.730.57170884.730.6748611
1.0640.02694161.740.24054922.740.43775063.740.57287164.740.6757783
1.0650.02734961.750.2430382.750.43933273.750.57403134.750.6766936
1.0660.02775721.760.24551272.760.44090913.760.57518784.760.677607
1.0670.02816441.770.24797332.770.44247983.770.57634144.770.6785184
1.0680.02857131.780.250422.780.44404483.780.57749184.780.6794279
1.0690.02897771.790.2528532.790.44560423.790.57863924.790.6803355
1.070.02938381.80.25527252.80.4471583.80.57978364.80.6812412
1.0710.02978951.810.25767862.810.44870633.810.5809254.810.6821451
1.0720.03019481.820.26007142.820.45024913.820.58206344.820.683047
1.0730.03059971.830.26245112.830.45178643.830.58319884.830.6839471
1.0740.03100431.840.26481782.840.45331833.840.58433124.840.6848454
1.0750.03140851.850.26717172.850.45484493.850.58546074.850.6857417
1.0760.03181231.860.26951292.860.4563663.860.58658734.860.6866363
1.0770.03221571.870.27184162.870.45788193.870.5877114.870.687529
1.0780.03261881.880.27415782.880.45939253.880.58883174.880.6884198
1.0790.03302141.890.27646182.890.46089783.890.58994964.890.6893089
1.080.03342381.90.27875362.90.4623983.90.59106464.90.6901961
1.0810.03382571.910.28103342.910.4638933.910.59217684.910.6910815
1.0820.03422731.920.28330122.920.46538293.920.59328614.920.6919651
1.0830.03462851.930.28555732.930.46686763.930.59439264.930.6928469
1.0840.03502931.940.28780172.940.46834733.940.59549624.940.6937269
1.0850.03542971.950.29003462.950.4698223.950.59659714.950.6946052
1.0860.03582981.960.29225612.960.47129173.960.59769524.960.6954817
1.0870.03622951.970.29446622.970.47275643.970.59879054.970.6963564
1.0880.03662891.980.29666522.980.47421633.980.59988314.980.6972293
1.0890.03702791.990.29885312.990.47567123.990.60097294.990.6981005
1.090.037426520.3010330.477121340.60206
1.0910.03782482.010.30319613.010.47856654.010.6031444

1.0920.03822262.020.30535143.020.48000694.020.6042261

1.0930.03862022.030.3074963.030.48144264.030.605305

1.0940.03901732.040.30963023.040.48287364.040.6063814

1.0950.03941412.050.31175393.050.48429984.050.607455

1.0960.03981062.060.31386723.060.48572144.060.608526

1.0970.04020662.070.31597033.070.48713844.070.6095944

1.0980.04060232.080.31806333.080.48855074.080.6106602

1.0990.04099772.090.32014633.090.48995854.090.6117233


Common logarithm table from 5 to 9.99


50.6989760.778151370.84509880.9030990.9542425
5.010.69983776.010.77887457.010.8457188.010.90363259.010.9547248
5.020.70070376.020.77959657.020.84633718.020.90417449.020.9552065
5.030.7015686.030.78031737.030.84695538.030.90471559.030.9556878
5.040.70243056.040.78103697.040.84757278.040.9052569.040.9561684
5.050.70329146.050.78175547.050.84818918.050.90579599.050.9566486
5.060.70415056.060.78247267.060.84880478.060.9063359.060.9571282
5.070.7050086.070.78318877.070.84941948.070.90687359.070.9576073
5.080.70586376.080.78390367.080.85003338.080.90741149.080.9580858
5.090.70671786.090.78461737.090.85064628.090.90794859.090.9585639
5.10.70757026.10.78532987.10.85125838.10.9084859.10.9590414
5.110.70842096.110.78604127.110.85186968.110.90902099.110.9595184
5.120.709276.120.78675147.120.852488.120.9095569.120.9599948
5.130.71011746.130.78746057.130.85308958.130.91009059.130.9604708
5.140.71096316.140.78816847.140.85369828.140.91062449.140.9609462
5.150.71180726.150.78887517.150.8543068.150.91115769.150.9614211
5.160.71264976.160.78958077.160.8549138.160.91169029.160.9618955
5.170.71349056.170.79028527.170.85551928.170.91222219.170.9623693
5.180.71432986.180.79098857.180.85612448.180.91275339.180.9628427
5.190.71516746.190.79169067.190.85672898.190.91328399.190.9633155
5.20.71600336.20.79239177.20.85733258.20.91381399.20.9637878
5.210.71683776.210.79309167.210.85793538.210.91434329.210.9642596
5.220.71767056.220.79379047.220.85853728.220.91487189.220.9647309
5.230.71850176.230.7944887.230.85913838.230.91539989.230.9652017
5.240.71933136.240.79518467.240.85973868.240.91592729.240.965672
5.250.72015936.250.795887.250.8603388.250.91645399.250.9661417
5.260.72098576.260.79657437.260.86093668.260.916989.260.966611
5.270.72181066.270.79726757.270.86153448.270.91750559.270.9670797
5.280.72263396.280.79795967.280.86213148.280.91803039.280.967548
5.290.72345576.290.79865067.290.86272758.290.91855459.290.9680157
5.30.72427596.30.79934057.30.86332298.30.91907819.30.9684829
5.310.72509456.310.80002947.310.86391748.310.9196019.310.9689497
5.320.72591166.320.80071717.320.86451118.320.92012339.320.9694159
5.330.72672726.330.80140377.330.8651048.330.9206459.330.9698816
5.340.72754136.340.80208937.340.86569618.340.92116619.340.9703469
5.350.72835386.350.80277377.350.86628738.350.92168659.350.9708116
5.360.72916486.360.80345717.360.86687788.360.92220639.360.9712758
5.370.72997436.370.80413947.370.86746758.370.92272559.370.9717396
5.380.73078236.380.80482077.380.86805648.380.9232449.380.9722028
5.390.73158886.390.80550097.390.86864448.390.9237629.390.9726656
5.40.73239386.40.806187.40.86923178.40.92427939.40.9731279
5.410.73319736.410.8068587.410.86981828.410.9247969.410.9735896
5.420.73399936.420.8075357.420.87040398.420.92531219.420.9740509
5.430.73479986.430.8082117.430.87098888.430.92582769.430.9745117
5.440.73559896.440.80888597.440.87157298.440.92634249.440.974972
5.450.73639656.450.80955977.450.87215638.450.92685679.450.9754318
5.460.73719266.460.81023257.460.87273888.460.92737049.460.9758911
5.470.73798736.470.81090437.470.87332068.470.92788349.470.97635
5.480.73878066.480.8115757.480.87390168.480.92839599.480.9768083
5.490.73957236.490.81224477.490.87448188.490.92890779.490.9772662
5.50.74036276.50.81291347.50.87506138.50.92941899.50.9777236
5.510.74115166.510.8135817.510.87563998.510.92992969.510.9781805
5.520.74193916.520.81424767.520.87621788.520.93043969.520.9786369
5.530.74272516.530.81491327.530.8767958.530.9309499.530.9790929
5.540.74350986.540.81557777.540.87737138.540.93145799.540.9795484
5.550.7442936.550.81624137.550.8779478.550.93196619.550.9800034
5.560.74507486.560.81690387.560.87852188.560.93247389.560.9804579
5.570.74585526.570.81756547.570.87909598.570.93298089.570.9809119
5.580.74663426.580.81822597.580.87966928.580.93348739.580.9813655
5.590.74741186.590.81888547.590.88024188.590.93399329.590.9818186
5.60.7481886.60.81954397.60.88081368.60.93449859.60.9822712
5.610.74896296.610.82020157.610.88138478.610.93500329.610.9827234
5.620.74973636.620.8208587.620.8819558.620.93550739.620.9831751
5.630.75050846.630.82151357.630.88252458.630.93601089.630.9836263
5.640.75127916.640.82216817.640.88309348.640.93651379.640.984077
5.650.75204846.650.82282167.650.88366148.650.93701619.650.9845273
5.660.75281646.660.82347427.660.88422888.660.93751799.660.9849771
5.670.75358316.670.82412587.670.88479548.670.93801919.670.9854265
5.680.75434836.680.82477657.680.88536128.680.93851979.680.9858754
5.690.75511236.690.82542617.690.88592638.690.93901989.690.9863238
5.70.75587496.70.82607487.70.88649078.70.93951939.70.9867717
5.710.75663616.710.82672257.710.88705448.710.94001829.710.9872192
5.720.7573966.720.82736937.720.88761738.720.94051659.720.9876663
5.730.75815466.730.82801517.730.88817958.730.94101429.730.9881128
5.740.75891196.740.82865997.740.8887418.740.94151149.740.988559
5.750.75966786.750.82930387.750.88930178.750.94200819.750.9890046
5.760.76042256.760.82994677.760.88986178.760.94250419.760.9894498
5.770.76117586.770.83058877.770.8904218.770.94299969.770.9898946
5.780.76192786.780.83122977.780.89097968.780.94349459.780.9903389
5.790.76267866.790.83186987.790.89153758.790.94398899.790.9907827
5.80.7634286.80.83250897.80.89209468.80.94448279.80.9912261
5.810.76417616.810.83314717.810.8926518.810.94497599.810.991669
5.820.7649236.820.83378447.820.89320688.820.94546869.820.9921115
5.830.76566866.830.83442077.830.89376188.830.94596079.830.9925535
5.840.76641286.840.83505617.840.89431618.840.94645239.840.9929951
5.850.76715596.850.83569067.850.89486978.850.94694339.850.9934362
5.860.76789766.860.83632417.860.89542258.860.94743379.860.9938769
5.870.76863816.870.83695677.87

Thursday, May 9

Write a Mixed Decimal


Mixed number: Mixed number is formed by associating a whole number with fraction numbers.

Decimal number: A number along decimal a point in it is called decimal number.

Mixed decimal number:  A number having a decimal point in its mixed format is mixed decimal number.

Example: 7.5 `3/6`.  Let us see how to write mixed decimal number.


Writing a mixed decimal:

Write a mixed decimal:

In the whole number part of mixed number the decimal point appears show that the number is mixed decimal.

It should be written as,

133.63 `1/5`

Conversion of mixed decimal into fraction:

Step 1: First see how many numbers present after the decimal point.

Step 2: Calculate number of 10’s equal to the counted digits after the decimal point.

Step 3: Put number of 10’s as denominator and the number is mixed decimal number.

Step 4: Convert the numerator mixed decimal number into fraction.

Step 5: Now simplify the terms by a common term.

Example problems for writing a mixed decimal:

Example: 1

Write the following mixed decimal number into fraction number.

12.5 2/3

Solution:

Given, mixed decimal number =12.5 2/3.

We have to add the 10 as the denominator and the mixed decimal number as numerator.

That is, `(125 2/3)/10`

= `(377/3)/10`

= `377/30`

=12`17/30`

Example: 2

Write the following mixed decimal number into fraction number.

5.22 1/2

Solution:

Given, mixed decimal number =5.22 1/2.

We have to add the 100 as the denominator and the mixed decimal number as numerator.

That is, `(522 1/2)/100`

= `(1045/2)/100`

= `1045/200`

=`209/20`

=1`9/20` .

Example: 3

Write the following mixed decimal number into fraction number.

15.123 1/5

Solution:

Given, mixed decimal number =15.123 1/5.

We have to add the 1000 as the denominator and the mixed decimal number as numerator.

That is, `(15123 1/5)/1000`

= `(75616/5)/1000`

= `75616/5000`

= 25 `616/5000`

= 25 `77/625` .

Answer: 25 `77/625` .

Practice problems for write a mixed decimal number:

Problem: 1

Write the following mixed decimal into mixed number.

5.9 3/4

Answer: 5`39/40`.

Problem: 2

Write the following mixed decimal into mixed number.

5.633 1/2 .

Answer: 5`1267/2000`.

Hypothesis Testing Variance


Hypothesis testing is the use of statistics  found in the probability that a specified hypothesis is correct. Hypothesis is specified as declaration which may or may not be accurate. In statistics two hypothesis testing are used. They are null hypothesis and alternative hypothesis. These two hypothesis tested are opposed to each other. In statistics the significance level is symbolized through alpha. Let us see about the probability of hypothesis testing variance.

Hypothesis testing variance

There are five constituent to either statistical test:

Null Hypothesis

Alternate Hypothesis

Test Statistic

Level of significance

Conclusion

Hypothesis testing variance

Consider the population is standard, we are able to test the variance of the method using the chi-square distribution through (n – 1) degrees of freedom.

To test a variance or standard deviation of a population to be exact normally distributed, we can utilize the χ2–test.

The χ2- test for a variance or standard deviation is not as robust as the samples for the population mean otherwise the population proportion.

Therefore it is necessary to while performing the χ2–test used for a variance that the population is usually circulated. The results can be deceptive if the population is not standard.

Examples for hypothesis testing variance

χ2- test for population variance

In a sample of size 16 drawn from a normal population standard deviation is 4 can you say that population standard deviation is 5.

Solution

Null hypothesis:

H0: The population standard deviation is 5

Test statistic:

χ2   =`(ns^2)/sigma^2` ~ χ2n-1

Level of significance:

α= 0.05 at 5% level of χ2  table values for 16 degrees of freedom is 24.996

Calculation:

n = 16, s = 4, σ = 5

χ2   =`(16xx16)/25 = 256/25`

χ2   = 10.24

Calculated value = 10.24

Table value = 24.996

Calculated value < Table value

Therefore the null hypothesis is accepted.

The population standard deviation is 5

Result

The population standard deviation is 5

Wednesday, May 8

Whole Set Fraction


This article is about whole set fraction. Whole set fraction is nothing but it is about the set of fractions. A fraction is a number that can be represented by an ordered pair of whole numbers `a/b` where `b!= 0`. Here a is represented as numerator and b as denominator. The tutors in tutor vista are always ready to help the students in any topics like whole set fraction. The online tutors help students in online. Tutor vista is the best tutoring website where many students follow this. Below we can see about the whole set of fraction.

whole set fractions

In set notation, the set of fractions is

F ={ `a/b` where a and b are whole numbers,  b` !=` 0 }

Two fractions that represent the same relative amount are termed to be equivalent fractions.

Proper Fraction:

When the numerator is less than the denominator then those fractions are called as Proper fraction.

Example: `2/3 `

Improper fraction:

When the numerator is greater than the denominator then this fraction is called as Improper fraction

Example: `7/5`

All the integers are simply a improper fraction

Example

3 is nothing but `3 / 1` which is an improper fraction

Mixed fraction:

Mixed fraction is a whole number with proper fraction

Example:  2 `1/3`

whole set fractions

Example 1:

Add `5/3`  + ` 8/3`

Here both the denominator is same

Add numerator alone.

`(5+8)/3`

`13/3`

Adding improper fraction with different denominator

Example 2:

Add `5/2`  + `4/3`

Here find LCM and solve to make the denominator equal

LCM of 2 and 3 is 6

`(5xx3)/ (2xx3) = 15/6`

`(4xx2)/ (3xx2) = 8/6`

So `(15+8)/6 = 23/6`

whole set fractions

Example 3: Add `3/11` +`6/11`

Solution

Here the denominators are same. So just add the numerator alone

` (3+6)/11`

`9/11` is the answer.

Example 4: Subtract `8/9` – `4/9`

Solution

Here the denominators are same. So just subtract the numerator alone.

`(8 - 4)/9`

`4/9`

Example 5: Multiply` 3/5` x `3/ 4 `

Solution

`3 / 5 ` x `3 / 4`

`(3xx3)/(5xx4) `

= `9 / 20 `

Sunday, May 5

Addition Angle Formulas


Addition angle formula is based on trigonometric functions. We are having  the addition angle formulas to find the value of  the trigonometric equations and values for the trigonometric angles.
                         Cos (A+B) = Cos A Cos B - Sin A Sin B
                         Cos (A-B) = Cos A Cos B + Sin A Sin B
                         Sin (A+B) = Sin A Cos B + Cos A Sin B
                         Sin (A-B) = Sin A Cos B - Cos A Sin B
                         Tan (A+B) = `(Tan A + Tan B)/(1 - Tan A Tan B)`
                         Tan (A-B) =  `(Tan A - Tan B)/(1 + Tan A Tan B)`
                         Here we will some problems based on addition angle formulas.

Addition Angle Problems:


Problem 1:
         Solve the following trigonometric function using Addition angle formula Sin 75o
Solution:
            Sin 75o
                 We can write sin 75o as Sin (45o + 30o)
                              We have the formula for Sin (A+B) = Sin A Cos B + Cos A Sin B
                              Where A = 45o and  B = 30o
                              Sin 45o = Cos 45 = `(1)/(sqrt(2))`
                              Sin 30 = `(1)/(2)`    Cos 30 = `(sqrt(3))/(2)`
                              Sin (45o + 30o) = Sin 45o Cos 30o + Cos 45o Sin 30o
                                                          =  `(1)/(sqrt(2))` `(sqrt(3))/(2)` `(1)/(sqrt(2))` `(1)/(2)`
                                                          = `(sqrt(3))/(2sqrt(2))` + `(1)/(2sqrt(2))`
                                                          = `(sqrt(3)+1)/(2sqrt(2))`
Problem 2:
       Solve the following trigonometric function using Addition angle formula Cos 135o
Solution:
               Cos 135o
                We can write Cos 135o as Sin (90o + 45o)
                              We have the formula for Cos (A+B) = Cos A Cos B - Sin A Sin B
                              Where A = 90o and  B = 45o
                              Sin 45o = Cos 45 = `(1)/(sqrt(2))`
                              Sin 90o = 1  Cos 90o = 0
                              Cos (90o + 45o) = Cos 90o Cos 45o - Sin 90o Sin 45o
                                                      = 0 . `(1)/(sqrt(2))` - 1 . `(1)/(sqrt(2))`
                                                      = 0 - `(1)/(sqrt(2))`
                                                      = - `(1)/(sqrt(2))`

Problem 3:


       Solve the following trigonometric function using Addition angle formula Tan 135o
Solution:
               Tan 135o
               We can write Tan 135o as Tan (180o - 45o)
                              We have the formula Tan (A - B) = `(Tan A - Tan B)/(1 + Tan A Tan B)`
                              Where A = 180o and  B = 45o
                              Tan 45o = 1 Tan 180o = 0
                              Tan 135o = `(Tan 180^o - Tan 45^o)/(1 + Tan 180^o Tan 45^o)`
                              Tan 135o = `"(0 - 1)/(1 + (0) (1)) `
                              Tan 135o = `(- 1)/(1)`
                              Tan 135o = -1

Saturday, May 4

Compute Percentages


In mathematics, a percentage is a way of expressing a number as a fraction of 100 (per cent meaning "per hundred" in French). It is often denoted using the percent sign, "%", or the abbreviation "pct". For example, 45% (read as "forty-five percent") is equal to 45 / 100, or 0.45. Let us see how to do percentages.                                                                                                                                           - Source from Wikipedia

How to compute percentages:


STEP 1: While begin the percentage` x / 100 ` = `(is) / (of)` . Out of hundred x may be the percentage, "is" denotes as fraction, and "of" denotes as whole.
STEP 2: If we are having the questions 80 : 40 percentage then we will write it as X = 40, is = 40 ("80 is"), and then of = as unknown value. Now the value is possible to write like this `40 / 100 ` = `80 / x` .
STEP 3: Let us do the cross multiplication. Now we can get a Constant value on 1 side and then multiply it with another side. Now we will get a result likes this 40x = 8,000.
STEP 4: Now you have to find out the x value. Where, x = `8000 / 40` = 200, now the x value will be 200.

How do you solve percentages some examples here:


Problem 1:
           In a question paper there is 80 questions. Laura took that test. If she gets 75% correct, how many questions did Laura missed?
Solution:
            Therefore total correct answers are 75% of 80 or else `75 / 100` × 80
            ` 75 / 100` × 80 = 60%
            So the question paper contains 80 questions and Laura got 60 exact answers, the number of questions Laura left is 80 − 60 = 20.
            Therefore Laura missed 20 questions.
Problem 2:
            Compute this, what is 85% of 15?
Solution:
Step 1: Compute the percent.
           The percent value is 85.
            P = 85
Step 2: Find out the base.
           The base is the number next the word OF, 15
            b = 15
Step 3: Identify the quantity.
           The calculation is the unknown.
            a =?
Step 4: Enter the value in the percent proportion formula.
         `a/ 15` = `85 / 100`
Step 5: Exercises the equation for the unknown.
           The Least Common Divisible of 15 and 100 is 100
     `100 / 1` * `a / 15` = `100 / 1` * `85 / 100`
            6.6a = 85
          ` (6.6a) / (6.6)` = `85 / (6.6)`
            a = 12.8
            12.8 is 85% of 15.


Practice problem for compute percentages:
Problem 1:
            What is the percentage of 67%?
Solution:
             = 0. 67.
Problem 2:
            What is percentage of 87% of 18?
Solution:
             = 15.66
            Therefore 15.66 is 87% of 18.

Friday, May 3

Taylor Polynomial Series


In mathematics, the Taylor series is a representation of a function as an infinite sum of terms calculated from the values of its derivatives at a single point. It is named after the English mathematician Brook Taylor. If the series is centered at zero, the series is also called a Maclaurin series, named after the Scottish mathematician Colin Maclaurin. It is common practice to use a finite number of terms of the series to approximate a function. The Taylor series may be regarded as the limit of the Taylor polynomials.  In the article we shall discuss about Taylor polynomial series.(Source: Wikipedia)



Taylor polynomial series:




Find the Taylor series for sin x.
    Sin x = `sum_(0)^oo` `((-1)^k)/((2k + 1)!)` x2k+1
The remainder term is not expressible in any simple way but can be estimated by using the Lagrange's form of the remainder. The coefficients
   `((-1)^k)/((2k + 1)!)`
are easily verified by calculating successive derivatives of f(x) = sin x and using the formulas
 ak=`(f^(k)(0))/(k!)`
To check convergence of the series, apply Lagrange's form for Ra(x); For each x`in` R. there exists Z such that
Rn(x) = `(f^(n + 1)(z))/((n + 1)!)` xn+1
Now |fn+1(z)| equals either |cos z| or |sin z| So, in either case,|fn+1 (z)|`<=`1 ,and
       |Rn(x) |`<=` | x |n+1 /(n+1)!
Since | x |n+1 /(n+1)!`->`0 as n `|->` `oo`  for all x`in` R, we can see that the remainder term |Rn(x)|`|->` 0 as n `|->` `oo`
 for all x`in` R. Thus the series representation is completely justified for all real x.
  Observe that our estimate for |Rn (x)|,
                                                    |Rn (x)|`<=`|x|n+1/(n+1)!
gives also a sense of the rate of convergence of the series for fixed x, for example, for | x|`<=` 1, we find
                                                    |Rn (x)|`<=`1/(n+1)!
Thus, if we want to calculate sin x on (-1, 1) to within .01, we need take only the first five terms of the series (n = 4) to achieve that degree of accuracy.
 Had we used the integral form for Rn (x) we would have obtained a similar estimate.



Sample problem for Taylor polynomial series:




Pro:  Evaluate the definite integral `int_0^1` Sin (x) dx
Sol:  The integrand has no anti derivative expressible in the terms of familiar functions. Howebver, we know how to find its Taylor series. we know that
      Sin t = t -`(t^3)/(3!)` + `(t^5)/(5!)` - `(t^7)/(7!)` + ----
Now if we substitute t = x, we have
     Sin (x) = X - `(x^3)/(3!)` + `(x^5)/(5!)` - `(x^7)/(7!)` + ----
In spite of the fact that we cannot antidifferentiate the function, we can antidifferentiate the Taylor series:
    `int_0^1` Sin (x) dx = `int_0^1` (X - `(x^3)/(3!)` + `(x^5)/(5!)` - `(x^7)/(7!)` + ----) dx
                            =(`(x^2)/(2)` -`(x^)/(4*3!)` + `(x^6)/(6*5!)`-`(x ^ 7)/(8*7!)`+ -----) |01
                            = (`(x^2)/(2)` -`(x^)/(4*3!)` + `(x^6)/(6*5!)`+`(x^7)/(8*7)` + ---)
Notice that this is an alternating series so we know that it converges. if we add up the first four terms, the pattern becomes ckear: the series converges to 0.2871

Sunday, April 21

Negative Integer Exponents


The exponents are which integer is placed in the power, of base numbers. It can be easily represent as, “a small number to the right side and above of base number”. It is called as exponents. These exponents have some of important rules and laws. Power with negative integer exponents is also one of the rules. Here we are going to explain about this negative integer exponent rule.

If we are having variables, which is containing the exponents and it have equal bases means, we can do some mathematical operations with the exponents. Those operations are called as the “laws of exponents” or “rules of exponents”. In this rule based negative integer rule of exponent is defined as following ways,

Definition for negative integer exponents:

It is otherwise called as power with negative exponent rules. This negative exponent rule is defined as, if m is a positive integer and x is a non-zero rational number, then it can be denoted as,

X-m = (1/x)^m (or)

= (1/x)^m

Which is (x)^-m is the reciprocal of (x)^m

And we adopt the same rule for rational exponents also. If p/q is a positive rational number means, and x>0 is a rational number, then

 X^ - (p/q) = (1/x)^ (p/q) = (1/x)^ (p/q) .

Which is, (x)^-(p/q) is the reciprocal of (x) ^(p/q) or the number obtained by raising the reciprocal of x to the exponent p/q.

For example: 1). 3^-2

= (1/3)^2

= (1/3)^-2

= -6 .

2). (4)^-(2/3)

= (1/4)^-(2/3)

= (1/4)^ (2/3)

This kind of exponentiation used for discovers the negative integer exponents and simplify the problems.


Example problems for negative integer exponents:

1) Solve: (8)^-(2/3)

Solution:

Given: (8)^-(2/3)

= (1/8)^ (2/3)

= [(1/8)^ (1/3)]^ 2

= (1/2)^2, since (1/2)^3 = 1/8

= 1/4 .

2) Solve: (32/243)^-(4/5)

Solution:

Given: (32/243)^-(4/5)

= (243/32)^(4/5)

= [(243/32)^(1/5)]^4

= [(3^5/2^5)^(1/5)]^4

= [((3/2)^5)^(1/5)]^4

= (3/2)^4

= 81/16.

3) Evaluate, and find the following negative integer exponent value:

Evaluate: (27/125)^-(2/3)  xx    (27/125)^-(4/3)

Solution:

 (27/125)^- (2/3) xx (27/125)^-(4/3)

= (125/25)^(2/3) xx (125/27)^(4/3)

= [(5^3/3^3)^(1/3)]^ 2 xx [(5^3/3^3)^(1/3)]^4

= [((5/3)^3)^(1/3)]^2 xx [((5/3)^3)^(1/3)]^4

= (5/3)^2 xx (5/3)^4

= (5/3)^6

= 15625/729.

These all are the explanations and example problems may clear about the negative integer exponents.

Saturday, April 20

Math Absolute Value Inequalities


In math, the absolute value |x| of a real number x is x's arithmetical value lacking view to its symbol. So, for example, 86 is the absolute value of both 86 and −86. Generalization of the absolute value for real numbers occurs in a extensive diversity of math settings. Consider an absolute value is also definite for the complex numbers, the quaternions, prepared rings, fields and vector spaces. The absolute value is strictly associated to the ideas of magnitude, distance, and norm in different math and physical contexts.

Properties of the Math absolute value inequalities

The absolute value fundamental properties are:

 |x| = sqrt(x^2)                                      (1) Basic

 |x| \ge 0                                            (2)     Non-negativity

 |x| = 0 \iff x = 0                            (3)     Positive-definiteness

 |xy| = |x||y|\,                                  (4)     Multiplicativeness

 |x+y| \le |x| + |y|                            (5)     Subadditivity

Another important property of the absolute value includes these are the:

 |-x| = |x|\,                                      (6)     Symmetry

|x - y| = 0 \iff x = y                     (7)     Identity of indiscernible (equivalent to positive-definiteness)

|x - y| \le |x - z| +|z - y|                 (8)     Triangle inequality (equivalent to sub additivity)

|x/y| = |x| / |y| \mbox{ (if } y \ne 0) \,                   (9)      Preservation of division (equivalent to multiplicativeness)

|x-y| \ge ||x| - |y||                           (10)     (Equivalent to sub additivity)

Math absolute value inequalities – Examples:

Math absolute value inequalities – Example 1:

|x - 5| < 3

Set up the two times inequality -3 < x -5 < 3 and then solve.

-3 < x – 5 < 3

2 < x < 8

In interval notation, the answer is (2, 8).
Math absolute value inequalities – Example 2:

|2x + 3| <=-8

This solution will involve setting up two separate inequalities and solving each.

2x + 3 <= -8

2x <=-11

x<=-11/2

Else

2x+3 >=8

2x >= 5

x>=5/2

In interval notation, the answer is (-oo, -11/2) U (5/2, oo) .
Math absolute value inequalities – Example 3:

|x - 9| < 4

Set up the two times inequality -4 < x -9 < 4 and then solve.

-4 < x – 9 < 4

5 < x < 13

In interval notation, the answer is (5, 13).

Math absolute value inequalities – Example 4:

|3x + 3| <= - 8

This solution will involve setting up two separate inequalities and solving each.

3x + 3 <= -8

 3x <=-11

x<=-11/3

Else

3x+3 >=8

 3x >= 5

x>=5/3

In interval notation, the answer is (-oo, -11/3) U (5/3, oo).

Friday, April 19

Negative Number Calculator


In this article we are discussing about subtracting negative number by using calculator. Negative number also real number. The negative number is represented as minus symbol “- “. Negative number or elements are less than zero such as -4, -7, -/3. A negative number may be parenthesized with its symbol, For example a subtracting is clearer if written (-7) + (−5) = -13 Using calculator we can the negative number.
Negative number calculator:

Let us see how to negative number using calculator.

Negative number is the similar as subtracting the corresponding negative number:

Example: (-7) + (-7) = -14

Negative number calculator – Example problems:

Example 1:

(-3) + (-4) = ?

Solution:

First enter the negative number in the calculator.

Then press the equal to button.

The solution is displayed on the calculator.

negative number calculator

The subtract solution is -7.

Example 2:

(-5) - (-4) = ?

Solution:

First enter the negative number in the calculator.

Then press the equal to button.

The solution is displayed on the calculator.

negative number calculator

The subtract solution is -1.

Example 3:

(-4) x (-4) = ?

Solution:

First enter the negative number in the calculator.

Then press the equal to button.

The solution is displayed on the calculator.

negative number calculator

The subtract solution is 16.

Example 4:

(-9) `-:` (-3) = ?

Solution:

First enter the negative number in the calculator.

Then press the equal to button.

The solution is displayed on the calculator.

negative number calculator

The subtract solution is 3.

Example 5:

(-10) x (-20) = ?

Solution:

First enter the negative number in the calculator.

Then press the equal to button.

The solution is displayed on the calculator.

negative number calculator

The subtract solution is 200.

Negative number calculator – practice problems:

Problem 1: (-5) + (-6)

Problem 2: (-4) – (-2)

Problem 3: (-9) x (-18)

Problem 4: (-5) `-:` (-20)

Negative number calculator – answer key:

Problem 1: -11

Problem 2: -2

Problem 3: 162

Problem 4: -0.25

Thursday, April 18

Solving Monotonicity and Concavity


A function is said to be rising on an interval [a, b] = I if f (z1) < f (z2) whenever z1 < z2 for z1, z2 `in` I. A function is said to be decreasing on an interval [a, b] = I if f (z1) > f (z2) whenever z1 < z2 for z1, z2 `in` I. A function which is strictly increasing or strictly decreasing on an interval is said to be monotonic on that interval. A function is said to be curved in up on an interval [a, b] if f ’’ (z) > 0 on [a, b]. A function is said to be curved in down on an interval [a, b] if f ’’ (z) < 0 on [a, b]. A point (c, f(c)) on the graph of y = f (z) is called an inflection point if the concavity changes at the point. (I.E., it is curved in up on some interval (a, c) and curved in down on some interval (c, b) or vice versa.)

Solving monotonicity and concavity - Examples:

Solving monotonicity and concavity - Example 1:

Find inflection points & determine concavity for f (x)

f ‘(x) = `(x^5)/20 + (x^4)/12 - (3x^3)/3 - 10`

f ’(x) = `(x^4)/4 + (x^3)/3 - 3(x^2)`

f ‘’ (x) = x3 + x2 – 3x

= x(x2 + x - 3)

f ‘‘(x) = 0

x = 0, -2.3, 1.3

Inflection pts: x= -2.3, 0, 1.3

Curved in up: (-2.3,0), (1.3,infinity)

Curved in down: (-oo,-2.3), (0,1.3)

Solving monotonicity and concavity

Solving monotonicity and concavity - More Examples:

Solving monotonicity and concavity - Example 1:

Find inflection points & determine concavity for f (x)

f (x) = `(x^5)/20 + (x^4)/12 - (x^3)/3 +10`

f ‘ (x) = `(x^4)/4 + (x^3)/3 - x^2`

f ‘’ (x) = x3 + x2 – 2x = x(x2 + x - 2)

= x (x+2) (x-1)

f ‘‘ (x) = 0

x = 0, -2, 1

f ’’(-5) < 0, f’’(-1) > 0, f ’’(.5) < 0, f ’’(10) > 0

Inflection pts: x=-2,0,1

Curved in up: (-2,0), (1,`oo` )

Curved in down: (`-oo` .,-2), (0,1)

Solving monotonicity and concavity

Wednesday, April 17

Trinomial Multiplication


In algebraic expression consisting of only one term is called a monomial, two terms is called a binomial and when there are three terms separated by an addition or a subtraction operation is called a trinomial. ‘Tri’ in the word trinomial means three and hence the name. It is also referred to as a polynomial as ‘poly’ means more than two terms. For example, a+3b-c consists of three terms a, b and c and hence a trinomial. In 3b, 3 is called the coefficient of b. In a given polynomial we come across like terms and unlike terms.

Like terms are the terms which have the same variable or literal but a different coefficient. For example, (3b, -7b);(5x2, 12x2);(-4xy, 7xy) are some of the like terms. Unlike terms as the name suggests are the terms which have different variables. For example, (7x, 8y); (4ab, -4ac); (2y2, -2x2) etc are some of the unlike terms.

It is not necessary that there would be only two like or unlike terms, it depends on the number of terms in the given polynomial. Now let us learn as to How do you multiply trinomials. There are two methods in which we can multiply trinomials, one is the horizontal method the other is the vertical method.

The steps to be followed in a Horizontal method of multiplication are as follows:
Example: Multiply (4x2-3x+5)(x2+5x-3)
Solution: First and second terms are chosen irrespective of the order
Let (4x2-3x+5) be the first term and (x2+5x-3) be the second term

Arrange the two polynomials horizontally
(4x2-3x+5) X (x2+5x-3)
Now distribute each of the terms of the first trinomial with each of the terms of the second trinomial
=4x2(x2+5x-3)- 3x(x2+5x-3) +5(x2+5x-3)
=4x4+20x3-12x2 - 3x3-15x2+9x +5x2+25x-15

Combine the like terms and simplify
=4x4+x3(20-3)+x2(-12-15+5)+ x(9+25) – 15
= 4x4+17x3-22x2+34x-15

The steps to be followed in a Vertical method of multiplication are as follows:
Example: Multiply (4x2-3x+5)(x2+5x-3)
The first and the second terms are chosen irrespective of the order
Let (4x2-3x+5) be the first term and (x2+5x-3) be the second term
Arrange the two polynomials in a vertical form
4x2-3x+5
X  x2+5x-3

Working from right towards left each term of the lower trinomial is multiplied with each of the terms of the upper trinomials. Then the products are written underneath the second trinomial in three rows in the order of the degree of each term and then the like terms simplified as shown below
4x2-3x+5
X  x2+5x-3
-12x2+ 9x – 15
+20x3-15x2 + 25x
4x4 - 3x3  + 5x2                      .
4x4+17x3-22x2+ 34x-15 is the final product!