I was computing the length of the curve $y=e^x$ between $x=1$ and $x=2$. When I input "arc length of e^x between 1 and 2" into WolframAlpha, it gives me only an approximation as follows:
However, using calculus, one obtains the precise value of the length:
Is this result too complicated for WolframAlpha so that WolframAlpha can only give an approximation? More generally, when does WolframAlpha refuse to give the precise value?