Question

Which of the following is equivalent to cos x?

A) TAN Y
B) TAN X
C) COS Y
D) SIN Y

Answer 1

D) sin Y

Step-by-step explanation

The given triangle is a right triangle.

This implies that that:

`x + y = 90 \degree`

Then we have

`y= 90 - x`

Recall that

`\cos(x) = \sin(90 - x)`

But

`90 - x = y`

When we do the substitution, we get,

`\cos(x) = \sin(y)`

Therefore cos(x) is a equivalent to sin(y).

The correct answer is D.