I really need help with the following calculus questions with a very detailed explanation.

4. Integrate: a) x2 b) 2x + 6x c) x(x + 3) d) x- e) e"+ 4e-3x 5. A critical point of a function f (x) is a point where its derivative is zero. A critical point can be a mini- mum or a maximum, distinguished by the sign of the curvature of the function d'f (x)/dxa, or a point of inflection. Find and classify the critical points for f (x) = 3x /5 - 12x.9. When AHW and R are constant, then d In P saw, a'T RTE a) Integrate this expression. b) Evaluate the constant of part a) if P. is the vapor pressure at temperature T. and P; at T2. c) Rewrite the integral of part a) as one term employing your constant from part b)