Question

If sina = root3/2 find 2cos2a - 1

Answer 1

Step-by-step explanation:

Sin A=√3/2 (given)

[We know Sin 60°= √3/2]

Therefore A=60°...

Substitute the value of A in 2Cos²A-1

So, 2Cos²60-1

[We know the value of Cos60° is 1/2.]

2(1/2)²-1.

2(1/4)-1

1/2-1. (Taking LCM)

1-2/2 = -1/2

So the answer is -1/2