Question

How do you graph `y=-sinx`?

Answer 1

This is y=sinx:
graph{y=sinx [-10, 10, -5, 5]}

This is y=-sinx:
graph{y=-sinx [-10, 10, -5, 5]}

Explanation:

Take your points from a sine graph and add a negative in front of the y co-ordinates, since the negative in the equation affects only the y co-ordinates.