Question

Suppose sin(x) = -3/5 and cos(x) < 0. What the value of cos(2x)?

A) -16/25
B) -7/25
C) 7/25
D) 16/25

Answer 1

Answer:it’s C

Explanation:

I just took it

Answer 2

The value of cos(2x) = 7/25

Hence, option C is true.

Explanation:

Using the trigonometric identity

cos 2x = 1 - 2sin²x

Given

• sin(x) = -3/5

• cos(x) < 0

so substituting the values

cos 2x = 1 - 2sin²x

= 1 - 2 (-3/5)²

= 1 - 2 (9/25)

= 1 - 18/25

= 7/25

Therefore,

The value of cos(2x) = 7/25

Hence, option C is true.