1. ## Please help me determine the equation of these sine graphs

im just so confused. I dont know how to do this. I need help..
Heres the graphs:

You don't have to do all of them, if you could just help me do one of them I should be able to do the rest on my own.
I mostly need help finding the period and the b value.
Thank you so much

2. b) $\displaystyle -3\sin x$ This is sin reflected in the x axis with a amplitude of 3
c) $\displaystyle 3 \sin 2x$ Once again has an amplitude of 3 and half the period
d) can also be determined, what do you think the period is? What do you think the min/max is?