Problem $3$: Consider the waveforms for sinusoidal, square, and triangular signals shown in the figure below. All three waves have the same period, $T,$ and amplitude, A and have zero mean values.

$($a$)$ Derive the expression for the RMS pressure of the square wave and triangular wave.

$($b$)$ Compare the value of the RMS pressure for sinusoidal, square, and triangular waves $($which value is the lowest? Which value is the highest?$)$