# Given that sin t= (-2/3) and that P(t) is a point in the 3rd quadrant, what is the cos of t?

##### 1 Answer

Mar 9, 2018

#### Answer:

See explanation.

#### Explanation:

If we have

#sin^2alpha+cos^2alpha=1#

If we substitute the given value we get:

The given equation has 2 solutions. To choose one we have to use the given information about the quadrant, in which the angle is located.

The angle is located in