Question

Cos 2A = (1-tan^2 A) / (1+ tan^2 A) then A=

Answer 1

$0≤A≤π/2$

Step-by-step explanation:

$\boxed{cos 2A= \frac{1 - tan ^{2}x A}{1 + tan^{2}A } } \\ we \: \: know \: \: that \: \:for \: \: cos2A\\ 0≤2A≤π \\ 0≤A≤ \frac{\pi}{2}$