Question

if tan a/2 = 1/2, then cos a=?​

Answer 1

Answer:

tan a/2 = 1/2

=> 2a = 2

=> a = 1

tan 1/2 = p/b

h= √ p^2 + b^ 2

h = √1 +4

h =√ 5

Cos A = b / h = 2 / √ 5