Question

Can someone help me find this cosine please?

Answer 1

I have to find the cosine(theta) of a circle. My x is 4, and my y is -(sqrt33).

Answer 2

Wouldn't this become 4/7? I just want to make sure I know how to do this...

Answer 3

@RadEn

Answer 4

find the length of hypo, first

Answer 5

r=sqrt(x^2+y^2)

Answer 6

yes, find r

Answer 7

That's what I'm asking. I got 4/7. I just want to be sure I know how to do that properly.

Answer 8

oh, that's cool :)

Answer 9

Well, to be more clear, I got 7 for r. And then I got 4/7, because cosine(theta) is x/r.

Answer 10

:)

Answer 11

dont forget about " quadrant ". in this case θ in the 4th quadrant, so cosine be positive, but if your question is find sin and tan, so it must be negative. because in the 4th quadrant only cosine be +