Find the area of the region that is bounded by the curves. (a) f(x) = 1 - x^2 and g(x) = x^2 - 1. (b) The curves y = sec x and y = tan x, x = 0 and x = pi/2. (c) The area bounded between f(x) = arctan x/x^2 and g(x) = arctan x/x^2 + 1 over the interval