$$\int_1^2 {{{{x^3} - 1} \over {{x^2}}}} $$ is equal to

If $$\int_0^{\pi / 2} \tan ^n(x) d x=k \int_0^{\pi / 2} \cot ^n(x) d x$$, then

$$\int_0^2 x e^x d x$$ is equal to

$$\int_2^4\{|x-2|+|x-3|\} d x$$ is equal to