1.4 Composition of functions
(1) Given the following functions f(x) and g(x), find the natural domain of the two possible compositions, i.e. Dfog and Dgof:
(a) f(x) = lnx, g(x) = √(x+3)
(b) f(x) = 2^(x), g(x) = x^(2) + 3x + 1
(c) f(x) = √(-x), g(x) = x^(4) + x^(2) + 6
(d) f(x) = (x+2)/(x-3), g(x) = 3^(x)
(2) Consider the following functions: f(x) = 1/x, g(x) = x^(2) + 1, h(x) = 2x^(2) - 3x + 4, w(x) = x^(2).
Write down expressions for the following compositions and determine the natural domain D of the resulting function:
(a) h(h(x))
(b) f(sin(w(x)))
(c) ln(h(x))
(d) f(w(√(x) + 1))
(e) f(g(h(x)))