precal question

Question

Find the terminal point P(x, y) on the unit circle determined by the given value of t.

t = − 3π/4

P(x, y) =

 

Answer 1

3pi/4 is 135 degrees, in the 2nd quadrant where x=-y

(x)^2 + (y)^2 = 1

(-y)^2 + (y)^2 = 1

2y^2 = 1

y^2 = 1/2

y = sqr(1/2)

x=-sqr(1/2)

terminal point is P(x,y) = (-sqr.5, sqr.5)