Question

Find cos θ if sin θ = -12/13 and tan θ > 0.

Answer 1

use sin^2x+cos^2x=1

Answer 2

If the sin is negative and the tangent is positive, you are in quadrant 3.

Answer 3

its in the 3rd quadrant where cos is negative... draw a triangle as you know the lengths of the opposite and hypotenuse find the adjacent side use pythagoras



find the length of a

and co(x) = - a/13

Answer 4

cosine is side adjacent over hypotenuse, negative in quadrant 3

Answer 5

is it -13/12? @Mertsj

Answer 6

What is the hypotenuse of the triangle?

Answer 7

13

Answer 8

cosine is side adjacent over hypotenuse so the hypotenuse has to be on the bottom.

Answer 9

my only option w 13 on the bottom then is -5/13...is that correct?

Answer 10

yes

Answer 11

thx:)