Here's the question you clicked on:
ChrisV
lim x>pi cot(x)
\[\lim_{x \rightarrow \pi} \cot(x)\]
\[\cot(\pi)=\frac{\cos(\pi)}{\sin(\pi)}\] is undefined because the denominator is zero. if the numeratore was also zero you would have to do more work to find the limit, but since the numerator is -1 you get something that looks like \[\frac{-1}{0}\] so there will be no limit
thanks should have been able to recognize that myself