Question

if sin(x)=1/3, what is/how do you find sin(-x)?

Answer 1

hint: sine is an odd function which means sin(-x) = -sin(x)

Answer 2

all odd functions have the property that f(-x) = -f(x)

Answer 3

one way is with a picture, and the definition of sin(x) = opp/hypotenuse

-x means go *clockwise* from the positive x-axis
by symmetry we see the opposite side is -1, and the hypotenuse is still +3
and sin(-x)= -1/3