Precalculus Question?

Question

(Refering 2 d unit circle)
x= cos
y=sin

how do you find the 2 values of Sine if the Cosine was given??

pls teach me f u cn im me @ [e-mail]

Answer 1

if you know cos x = a,
then
sin^2 x = 1- cos^2 x = 1- a^2
so sin x = +- sqrt( 1-a^2) ~

Answer 2

You can use the relationship (sin(x))^2 + (cos(x))^2 = 1. Given the value of cos, there are two values of sin that satisfy the relationship. They will be each other's additive opposites.