2.1.56 Calculation of limits
Condition: Find the limit: \[ \lim _{x \rightarrow \frac{\pi}{2}}\left(\frac{x}{\cot x}-\frac{\pi}{2 \cos x}\right) \text {. } \]
Calculation of various limits, using L'Hopital's rule, remarkable limits, power series, equivalent values of various other methods.