Question

If cos O =-2/5 and tan O > 0 what is the value of sin O

Answer 1

negative square root 21 over 5.

Explanation:

mathGiven that for an angle ,

We are to find the value of

We know that

Cosine is negative in Quadrant II and Quadrant III.

Tangent is positive in Quadrant 1 and Quadrant III.

So, the given angle lies in the Quadrant III.

We will be using the following trigonometric identity:

We have

Since the angle lies in Quadrant III and sine is negative in that quadrant, so

Thus, option (B) is correct.