Find the amplitude and period for the given trigonometric expression below.

$P\left(x\right)=3\sin \left(4x\right)$

Draw the graph of the following trigonometric function using transformation from the basic trigonometric function.

$f\left(x\right)=2\cos \left(\frac{\pi x}{18}\right)+3$

Describe the following graph using a cosine function.