Answer
The function is $f{-1}(\$50,000)$.
Work Step by Step
The function f(t) represents the amount that an investment that will grow in t years. Its inverse function, $f{-1}(x)$ will represent the number of years taken for the growth.
Therefore, $f{-1}(\$50,000)$ gives the number of years after 2004 needed for the investment to reach $50,000.
