Finding the Displacement, Period, and Frequency, and Graphing a Function

For the given functions,

(a) Find the maximum displacement of an object.
(b) Find the period or the time required for one vibration.
(c) Find the frequency.
(d) Sketch the graph.

ⓐ $y=5sin\left(3t\right)$
ⓑ $y=6cos\left(\pi t\right)$
ⓒ $y=5cos\left(\frac{\pi }{2}t\right)$

Its source prints no answer for this problem, so there's nothing to check against.

OpenStax, Precalculus 2e · §7.6 Modeling with Trigonometric Functions · Example 8