Trigonometry - Trigonometric Graphs and Parameters

The voltage, \(y\) (in voltage), in an alternating current (A.C) circuit, it is given by \(y = 6 \cos(4\pi t)\), where \(t\) is the time in seconds.

1. Find the amplitude and the period of this function.
2. Sketch the graph of \(y = 6 \cos(4\pi t)\) for \( 0 \leq t \leq \frac{9}{8}\).