Question

Write the inverse function for the function, ƒ(x) = 1/2x + 4. Then, find the value of ƒ -1(4). Type your answers in the box. ƒ -1(x) = ______ a0 x _____a1 ______ a2 ƒ -1(4) = _______ a3

Answer 1

As you know, to get the inverse of any expression, we start off by switching the variables about and then solving for "y",

$\bf \stackrel{f(x)}{y}=\cfrac{1}{2}x+4\qquad \qquad \stackrel{inverse}{\underline{x}=\cfrac{1}{2}\underline{y}+4}\implies x-4=\cfrac{1}{2}y \\\\\\ 2x-8=\stackrel{f^{-1}(x)}{y} \\\\\\ f^{-1}(4)=2(4)-8\implies f^{-1}(4)=0$