Here's why:

* Wavelength (λ): The distance between two consecutive crests or troughs of a wave.

* Velocity (v): The speed at which the wave travels.

* Frequency (f): The number of wave cycles that pass a point in one second.

The relationship between these three is:

v = λf

This means:

* Velocity (v) is directly proportional to wavelength (λ) and frequency (f).

* If the wavelength increases, the velocity increases if the frequency remains the same.

* If the frequency increases, the velocity increases if the wavelength remains the same.

So, the equation that shows how wavelength is related to velocity and frequency is v = λf, or rewritten to solve for wavelength: λ = v/f.