Precalculus Qestion?

Question

(regarding d unit circle)
x=cos
y=sin

how do u find the 2 values of sine if u were given the cosine??

for example ur cosine is -(5/13) or 7/12 or something like that.... cn anyone explain 2 me how it's done? .... how do u do that? pls help... i hav a test 2moro



how do u use d pythagorean 2 solve this?

Answer 1

sine = side opposite over hypotenuse. so if sine is 7/12, 7=side opposite and 12=hypotenuse. But by Pythagorean theorem, hypotenuse = √[side opp^2 + side adjacent^2] If the side opposite = 7, and hypotenuse = 12, you can find side adjacent

side adjacent = √[hypotenuse^2 - side opp^2]; for the example we get side adjacent = √[12^2 - 7^2] = √[144 - 49] = √[95]

Now cosine = side adjacent over hypotenuse, = √[95] / 12.

You can also do it if you are given cos, then you can find the sin

Answer 2

use sin x^2 + cos x^2 = 1, to find