Write an expression that completes a fundamental identity for the following function.
sin(−z) = ?
Choose the correct answer below.
A. -sin z
B. sin z
C. - cos z
D. cos z
Try this pick a number say...20
sin 20 = ? then try sin (-20)= ? what do you find ?
$\sin(90)=1$
$\sin(-90)=-1$
$\sin(270)=-1$
$\sin(-270)=1$
Apparently, $\sin(-n) = - \sin(n)$