Suppose [math]w[/math] is a function describing the height of a wave, where [math]w[/math] depends on [math]x[/math], [math]t[/math], and [math]c[/math]. Here, [math]x[/math] is the distance variable, [math]t[/math] is the time variable, and [math]c[/math] is the wave speed. If [math]w[/math] satisfies the second-order partial differential equation[br] [math]\frac{\partial^2w}{\partial t^2}=c^2\frac{\partial^2w}{\partial x^2}[/math] [br]then we say that [math]w[/math] satisfies the [b]wave equation[/b].

[i]This applet was developed for use with [url=https://www.pearson.com/en-us/subject-catalog/p/interactive-calculus-early-transcendentals-single-variable/P200000009666]Interactive Calculus[/url], published by Pearson.[/i][br]