This is an example of how the graph should look like. What you can do is to find the sine of 2 angles, let's choose pi and 3pi/2. Find the function for these values
[tex]\begin{gathered} -3\cdot\sin \pi=-3\cdot0=0 \\ -3\cdot\sin (\frac{3\pi}{2})=-3\cdot-1=3 \end{gathered}[/tex]Plot these points and graph the function: (3.14,0) and (4.71,-3)