FX Equation attempts to automatically format most equations. Unfortunately many expressions are ambiguous, sin2x for example. We wanted FX Equation to automatically recognize sin2x while still allowing you to get sin 2x if you wish. The solution was where you put a space. If you leave a space between sin and 2x, you will get sin 2x. Without the space you get sin2x. This is much easier to use than describe. In general, if FX Equation does not format your equation the way you expect, try entering a space between things.
