I'm a physics student and I seem to be having trouble accepting a glaring inconsistent with regards to $i^2$. From all the math sources I see, $i^2$ is defined as -1. While, on the other hand, physicists seem to think that $i^2 = 1$ so that $-i^2 = -1$.
So, which is right and why?
I've not once seen $i^2=1$ in any physics text I've read. (I am a former physicist-in-training.) $i$ is defined to be such that $i^2=-1$ (or something equivalent) in every text I've read.