Math, asked by sairam1729, 1 year ago

how can we calculate the value of cos20 without a calculator.

Answers

Answered by Anonymous

u have to use cos table for it
it is available easily in books and charts separately

cos 20=0.4080

sairam1729: any another possibility

Anonymous: not in this case

Anonymous: But u can do it for multiples of 15 degrees

sairam1729: how.. could u explain

Anonymous: it has pre calculated value

Anonymous: like we know sin 30=1/2

sairam1729: so what is the value of sin15

Answered by Gpati04

put the value of 20 in radians. In radians, it will be 20*3.14/180.

Expand cos theta in series by

cos theta = 1- theta^3/3!+ theta^5/5! -

This way you can find the cos theta value.

sairam1729: could u solve it

Previous Question

Next Question