# How do you find cos if sin= 5/13?

##### 2 Answers

#### Explanation:

If

then

By Pythagorean Theorem

If

then

and

However, we need to note that if the angle is in Quadrant II then the

so

or

(the angle can't be in Q III or Q IV, since

#### Explanation:

Another way.

sin x > 0 --> x is either in Quadrant 1 or Quadrant 2.

If x is in Quadrant 1, then, cos x > 0 -->

If x is in Quadrant 2, then, cos < 0 -->