$\left(30\degree,0\right)$  

 $\left(45\degree,0\right)$  

 $60\degree,0$  

 $\left(90\degree,0\right)$  

 $\left(180\degree,0\right)$  

$f\left(x\right)=\frac{1}{2}\sin\left(\frac{1}{2}x\right)$

$f\left(x\right)=\frac{1}{2}\sin\left(2x\right)$

$f\left(x\right)=\frac{1}{2}\cos\left(2x\right)$

$f\left(x\right)=2\cos\left(\frac{1}{2}x\right)$

$f\left(x\right)=2\cos\left(2x\right)$

$y=2\sin x,\ 0\degree≤x≤270\degree$

$y=2\cos4x,\ \ 0\degree≤x≤270\degree$

$y=4\sin2x,\ \ 0\degree≤x≤270\degree$

$y=4\cos2x,\ \ 0\degree≤x≤270\degree$

$y=4\sin4x,\ \ 0\degree≤x≤270\degree$