Question

What does sin(-u) equal? . . . . . . . PLEASE HELP!!!

Answer 1

Answer:

-sin(u)

Step-by-step explanation:

This is a Trig identity.  The best way to understand this is to start at zero degrees.  +u would move counterclockwise, while -u moves clockwise.  The sine function gives you how far in the y-direction you are from the x-axis.  Since you're moving the same amount by going u degrees (or u radians) around the circle as you would going -u degrees (or -u radians), your distance from the x-axis is the same.  But it reflects over the x-axis, so the two outcomes are inverses of each other.