## anonymous one year ago Find cos theta if sin theta =-5/13 and tan theta>0

1. freckles

$\sin^2(x)+\cos^2(x)=1 \\ (\sin(x))^2+(\cos(x))^2=1$

2. freckles

replace sin(x) with -5/13

3. freckles

and solve for cos(x)

4. freckles

since tangent is positive and sine is negative then cosine is also negative.

5. freckles

$(\frac{-5}{13})^2+(\cos(x))^2=1$ do you know how to solve this equation for cos(x)?

6. anonymous

Isolate cos x

7. freckles

yes that is what we need to do