Question

How would you graph y = -3 sin x.

Answer 1

Start with the graph of sin x...which you should know. Or look it up if you don't.
The "-" flips it over the x-axis...so everything above goes below and everything below goes above
The 3 stretches it out...so the peaks and troughs will be at 3 and -3 rather than 1 and -1

Answer 2

I do not understand