## College Algebra (11th Edition)

$\frac{\sqrt{3}}{27}$
Substitute $\frac{-5}{2}$ to x. $f(\frac{-5}{2})$ $=3^{\frac{-5}{2}}$ Use the rule $a^{-b}=\frac{1}{a^b}, b\gt0$. $=\frac{1}{3^{\frac{5}{2}}}$ $=\frac{1\times3^{\frac{1}{2}}}{3^{\frac{5}{2}}\times3^{\frac{1}{2}}}$ Rationalize the denominator by multiplying $3^{\frac{1}{2}}$ to the numerator and denominator. $=\frac{3^{\frac{1}{2}}}{3^{\frac{6}{2}}}$ Simplify. $=\frac{3^{\frac{1}{2}}}{3^3}$ $=\frac{\sqrt{3}}{27}$