Please help me with these study guide problems. Show all work so I can verify my own work.

Imagine the graph of f(x) = x2 . Does f have a minimum value for x in the following intervals?

(a) I = [ -2, 3]

(b) I = [ -2, 3)

(c) I = ( -2, 3]

(d) I = [ -2, 1)

(e) I = ( -2, 1]

4. Find the extrema of the function f(x) = Vx (x + 1) and the intervals on which its graph is concave up or concave down. 5. Find the extrema and the coordinates of the points of inflection for the graph of f(x) = sin x - 2cosx on the interval [0,27]