Question

A + B = 90 degree and A = 2B then find the value of cos2B​

Answer 1

Answer:

Hope it helps

Step-by-step explanation:

Given, A + B = 90° and A= 2B

so 2B+B = 90°

3B = 90°

B = 30°

cos 2B = cos 2(30°)

= cos 60°

= 1/2

cos²B = cos²(30°)

= (√3/2)²

= 3/4