For each pair of functions, find f(g(x))
For each pair of functions, find f(g(x))
For each pair of functions, find f(g(x))
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Property <strong>of</strong> InversesIf f and f 1 are inverses, then f(a) = b if and only if f 1 (b) = a.ex. Let f(x) x 4 and represent its inverse as f 1 (x) = x + 4.Evaluate f(6). Evaluate f 1 (2).Because f(x) and f 1 (x) are inverses, f(6) = 2 and f 1 (2) = 6.When the inverse <strong>of</strong> a function is a function, the original function isonetoone. Recall that the vertical line test can be used to determinewhether a relation is a function. Similarly, the horizontal line test can beused to determine whether the inverse <strong>of</strong> a function is also a function.3
Ex. 2 Find the inverse <strong>of</strong> <strong>each</strong> function. Then graph the function andits inverse.a. f(x) = 2x 5b. f(x) = x 2 + 14
Verifying Inverses You can determine whether two <strong>functions</strong> areinverses by <strong>find</strong>ing both <strong>of</strong> their compositions. If both compositionsequal the identity function I(x) = x, then the <strong>functions</strong> are inverse<strong>functions</strong>.Ex. 3 Determine whether <strong>each</strong> <strong>pair</strong> <strong>of</strong> <strong>functions</strong> are inverse <strong>functions</strong>.Explain your reasoning.a. f(x) = 3x + 9 and g(x) = 1/3x 3b. f(x) = 4x 2 and g(x) = 2√x5
ASSN: p. 420, 421 9,11,15,17,19,21,23,27,29,31,37,39,43,45Review p. 422 5775 odd6