## Calculus Concepts: An Informal Approach to the Mathematics of Change 5th Edition

$r(4)\approx10.498$ $r(-.5)=r(-\frac{1}{2})$ $r(-\frac{1}{2})\approx.745$
$r(w)=1.8^{w}$ $r(4)=1.8^{4}$ $r(4)\approx10.498$ $r(-.5)=r(-\frac{1}{2})=1.8^{-\frac{1}{2}}$ $r(-\frac{1}{2})=\frac{1}{\sqrt 1.8}$ (This is because $a^{-b}=\frac{1}{a^{b}}$ and $a^{\frac{1}{2}}=\sqrt a$) $r(-\frac{1}{2})\approx.745$ (You could rationalize the fraction but it isn't necessary).