SSC CHSL 2025 PYQ — Question 72

Given:

sin2A = 3/5

By the formula:

sin²θ + cos²θ = 1

sin²2A + cos²2A = 1

(3/5)² + cos²2A = 1

9/25 + cos²2A = 1

cos²2A = 1 − 9/25

cos²2A = 16/25

cos2A = 4/5