This should be really obvious, but I can't quite get my head round it:
I have a complex number $z$. I want to reflect it about an axis specified by an angle $\theta$.
I thought, this should simply be, rotate $z$ by $\theta$, flip it (conj), then rotate by $-\theta$.
But this just gives $z^* (e^{-i\theta})^* e^{i\theta} $...
but this can't be right - as it's just $z^*$ rotated by angle $2\theta$, surely?