Question

If tan5A=1. Find Cos 5A.

Answer 1

Answer:

tan A =1/5

tan= P/B

let P/B= x/5x

Hypotheses =

H^2=P^2+B^2

H^2= x^2+25x^2

H^2= 26x^2

H=√26x

cos = B/H

5x/√25x

5/√25

1/√5

cos 5A=

5/√5

I think 5/√5 is the correct answer.