Find \( f(g(x)) \) and \( g(f(x)) \) and determine whether the pair of functions \( f \) and \( g \) are inverses of each other. \( f(x)=9 x-8 \) and \( g(x)=\frac{x+9}{8} \) a. \( f(g(x))=\frac{9 x+17}{8} \) (Simplify your answer. Use integers or fractions for any numbers in the expression.) b. \( g(f(x))=\square \) (Simplify your answer. Use integers or fractions for any numbers in the expression.)
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To find \( f(g(x)) \) and \( g(f(x)) \) for the functions \( f(x) = 9x - 8 \) and \( g(x) = \frac{x + 9}{8} \): a. First, we calculate \( f(g(x)) \). \[ g(x) = \frac{x+9}{8} \] Now substituting \( g(x) \) into \( f \): \[ f(g(x)) = f\left(\frac{x+9}{8}\right) = 9\left(\frac{x+9}{8}\right) - 8 \] \[ = \frac{9(x+9)}{8} - 8 = \frac{9x + 81}{8} - \frac{64}{8} = \frac{9x + 17}{8} \] So, you are correct that \( f(g(x)) = \frac{9x + 17}{8} \). b. Now, let's compute \( g(f(x)) \): \[ f(x) = 9x - 8 \] Now substituting \( f(x) \) into \( g \): \[ g(f(x)) = g(9x - 8) = \frac{(9x - 8) + 9}{8} \] \[ = \frac{9x - 8 + 9}{8} = \frac{9x + 1}{8} \] Thus, \( g(f(x)) = \frac{9x + 1}{8} \). To determine if \( f \) and \( g \) are inverses of each other, we check: 1. \( f(g(x)) \) should equal \( x \). 2. \( g(f(x)) \) should equal \( x \). From our calculations: - \( f(g(x)) = \frac{9x + 17}{8} \) which does not equal \( x \). - \( g(f(x)) = \frac{9x + 1}{8} \) which also does not equal \( x \). Therefore, \( f \) and \( g \) are **not** inverses of each other.