Is $\cot(x)=\frac{1}{\tan(x)}$? I just found in some place say that $\cot(x)=\frac{1}{\tan(x)}$. 
If you think about it as a function they are definitely not same. but if you think about as a relation between angle in a right angle triangle and its side they will be equal. 
so the question is its right to say they are equal or not( at least pedagogically)?
Update:-
Even wolfram alpha and Desmos say they are not equal ( have different domain).

Pedagogically, we say that that equality holds. We have to fudge it a bit on where the functions are defined (which is sometimes achieved by allowing $\tan(x)$ to be infinite) but we generally say that that equality holds.
