How can I make a sin wave that has double the wavelength of $a - b$, such that two consecutive zero points on the line are through a and b. And that the peak of the wave in between $a$ and $b$ is at $$\frac { a+b }{ 2 } $$
What is the equation of such a wave?
See the below diagram (Ignore my paint skills):
$$\sin\left(\frac{\pi(x-A)}{B-A}\right)$$