Sine Wave with Oscillating Half-wavelength

Question

What's the equation of a sine wave where the length of $\frac{λ}{2}$ oscillates, say between 2 and 3?

Thanks.

Answer 1

Multiplying by a constant inside the brackets stretches in the $x$ direction

e.g. $y=sin (2x)$ has wavelength 180 degrees instead of 360 degrees.

If we work in radians you'll need $sin({\pi} x)$ to make a wavelength of 2 and half the wavelength will be 1. By chance, since the wave repeats, it's also between 2 and 3.

Here is a graph of it on Desmos.

https://www.desmos.com/calculator/aqfzl4g1p4