# Proving a function satisfies a functional equation

## Lesson

Does $$f(x) = \sqrt{x}$$ satisfy $$f(x - y) = \dfrac{f(x)}{f(y)}?$$ If so, prove it.
Does $$f(x) = \dfrac{1}{x^2}$$ satisfy $$f(xy) = f(x)f(y)?$$ If so, prove it.