Express each function as a composition of two or more functions. Verify your choice of functions.
a. \(f(x) = 2^{3x - 1}\)
b. \(g(x) = \dfrac{3}{2\sin(x) - 1}\)
Solution
b. Approach 3
We can express \(g(x) = \dfrac{3}{2\sin(x) - 1}\) as the composition of three functions.
For example, if \(p(x) = \sin(x)\), \(q(x) = 2x - 1\), and \(r(x) = \dfrac{3}{x}\), then
\(r(q({\color{BrickRed}p(x)}))\)
\( = r(q({\color{BrickRed}\sin(x)})), \qquad \text{where } q({\color{BrickRed}\sin(x)}) = 2{\color{BrickRed}\sin(x)} - 1\)
\( = r({\color{NavyBlue}2\sin(x) - 1})\)
\( = \dfrac{3}{{\color{NavyBlue}2\sin(x) - 1}}\)
Thus, \(g(x) = (r \circ q \circ p)(x)\) when \(p(x) = \sin(x)\), \(q(x) = 2x - 1\), and \(r(x) = \dfrac{3}{x}\).