If cosA = 1 - 2sin2A, then what is the value of cos2A?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 1 - 2sin2A.
cosA = 1 − 2sin2A
We know that, 1 − 2sin2A = cos2A
So,
cosA = cos2A
⇒ cos2A = cosA = 1 − 2sin2A