On my calculator $\tan^{-1}$ is used to calculate the $\arctan$, but $\tan^{-1}$ actually is $\cot$. $\cot$ and $\arctan$ are not the same thing though. Am I missing something or is the labeling of my Casio fx-991ES really wrong?
To make the question more clear: Is $\arctan = \tan^{-1}$ correct?
Best Answer
Calculators have to save space on the labels, therefore $\tan^{-1}$ is more convenient than $\arctan$.
Moreover, the notation $f^{-1}$ conventionally denotes the functional inverse of $f$. It's rare to write $f^{-1}$ meaning $1/f$.
On my calculator, for example, $\sin^{-1}$ and $\cos^{-1}$ are used in place of the more correct (in my opinion, since less confusing) $\arcsin$ and $\arccos$.