Problem $3$ Sinusoidal Intro

The left$-$hand plot shows a sinusoidal wave at hat$(t)=0.$ The right$-$hand plot is the amplitude of the position $x=\frac{3}{2}{x}_0$ as a function of time. $($a$)$ What is the speed of the wave? $($b$)$ Write down a function $y(x,t)$ that describes the displacement at any given time and position.

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