# How do you graph y = -2 sin 2x?

For any general sinusoidal trigonometric equation of form $y = a \sin b x$, a is the amplitude which represents the maximum displacement from the x axis, and $\frac{2 \pi}{b}$ is the period which represents the amount of radians required for a full cycle of the graph.
So in this case, a=-2, period = $\frac{2 \pi}{2} = \pi r a d$
This means that the graph has maximum displacement 2 and completes a full cycle in $\pi$ rad.