Unit circle

Question

If point p=(-radical2/2,y) is on the unit circle in quad 3, what's the value of y?

Answer 1

Step 1:

The point is is on the unit circle in Quadrant .

Since the point is on the unit circle is .

Find the -value.

Substitute in the unit circle.

Since -coordinate must be negative in Quadrant .

Thus,

Solution:

The value of is