Green flag to reset. To solve a differential equation with Euler's method, press C for a first-order one or D for a second-order one. E.g. press D, then enter -y, 0, 1 for a sine wave (second order ones don't always seem to work when x<0 but I don't care now since y''(x) = -y works) Press A for ordinary graph, B for slope field. (use * for multiplication) Press s to toggle display variables (width & height must be even). (I think this might be one of the most fun ways to make a sine wave. It would be a really inefficient sin implementation because it'd take linear time, but for a sine wave that's fine, although it will get a bigger error as x grows...)
