could someone explain why the following equation is incorrect?
$\displaystyle \frac{d^2}{dx^2}\int^1 _{-1} \log|x-t|dt$=$\displaystyle \int^1_{-1}\frac{d^2}{dx^2}\log|x-t|dt$=$\displaystyle \int_{-1}^1 \frac{-1}{(x-t)^2}dt$
could someone explain why the following equation is incorrect?
$\displaystyle \frac{d^2}{dx^2}\int^1 _{-1} \log|x-t|dt$=$\displaystyle \int^1_{-1}\frac{d^2}{dx^2}\log|x-t|dt$=$\displaystyle \int_{-1}^1 \frac{-1}{(x-t)^2}dt$