Fan of lasers.
Lasers are awesome.
If F→G is a consequence of F, then so is ¬G→¬F. A direct proof?
asked Mar 26 '13 at 16:02
Suppose that $f(x)$ is continuous on $(0, \infty)$ such that for all $x > 0$,$f(x^2) = f(x)$. Prove that $f$ is a constant function.