how do i do? Amlplitude and period of sine and cosine functions

y=-1/3sin(2x)
(if u can put a graph for me and explain it)

The period = 2*pi/2 = pi.

Amplitude = 1/3 (graph will be reflected through the x-axis since the constant multiplier is negative. In this case.)

Plot the extrema and zeros: (0 , 0) , (-1/3 , pi/4) , (0 , pi/2) , (1/3 , 3*pi/4) , (0 , pi). This is the first period, on the interval [0 , pi.] Repeat the pattern for as many periods as you wish to graph.