## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$V^{-1}$ is used to calculate the number of years after 2008, after which the stamp will reach a given value.
If V(t) assigns (a value) to (the number of years passed), then $V^{-1}(t)$ assigns (a number of years) to (a given value in dollars). $V^{-1}(t)$ could be used on a given value of the stamp to determine how many years since 2008 will pass until the stamp achieves that value.