Find the points of relative extrema, the intervals on which the following functions are increasing, and those

Question:

Find the points of relative extrema, the intervals on which the following functions are increasing, and those on which they are decreasing:
(a) f(x) := x + 1/x for x ≠ 0.
(b) g(x) := x/(x2 + 1) for x ∈ R;
(c) h(x) := √x - 2√x + 2 for x > 0.
(d) k(x) := 2x + 1/x2 for x ≠ 0.