I think it's easiest to explain with an example. (Make sure calc is on Radian mode.)
Y1 = 5sin(x)
The minimum Y value that the equation will reach is -5. The maximum Y value that the equation will reach is 5.
One period (wavelength) of 5sin(x) is 2pi, so…
The ratio of X:Y needed for the graphing window to be square is 4.7:3.1.
With that given information (Xmin, Xmax, minimum and maximum Y values of equation), how do you go about ensuring that the graphing window is square, and that you are able to see minimum and maximum Y values.
(Note: The fact that Xmin was 0 really messed me up, and I think what I'm asking might be impossible if it is 0. So, if you need to make Xmin=-2pi (so that two periods are shown) in order to solve this problem, go ahead.)