Question

How do I figure out what sin(theta - pi) equals? The answer choices are (a) cos(theta) (b) -sin(theta) or (c) sin(theta)

Answer 1

Do you know the difference formula for sine?

Answer 2

try this
\[ \large \sin(A+B)=\sin A\cdot\cos B+\sin B\cdot\cos A \]
and remember that
\[ \large \sin\pi=0 \]

Answer 3

sum formula works to since any difference can be written as a sum

Answer 4

right.
\[ \large \sin(A-B)=\sin A\cdot\cos B-\sin B\cdot\cos A \]
sorry about the typo.