In the problem, t is a real number and P = (x, y) is the point on the unit circle that corresponds to t.

Question

Find the exact value of the indicated trigonometric function of t.

Find sin t.

Answer 1

sint = (sqr65)/9

(4/9, sqr65/9) = (x,y) = (rcost, rsint) = (cost, sint) since r=1. It's a unit circle. x=rcost, y=rsint

r^2 = x^2 + y^2

for a unit circle

with center at the origin

the equation is

x^2 + y^2 = 1