If $[\cdot]$ denotes the greatest integer function, then $\int_1^4 x[x] dx$ is equal to

If $\int_1^a (2x + 1) dx = 5$, then the sum of the values of $a$ is..

The area of the shaded region is ... sq.units.

$\int_0^3 \sqrt{9 - x^2} dx = $