Answer
$\int_{1}^{6} x^{-4}~dx = \frac{215}{648}$
Work Step by Step
We can find the area under the graph:
$\int_{1}^{6} x^{-4}~dx$
$=-\frac{1}{3}x^{-3}~\vert_{1}^{6}$
$=-\frac{1}{3}(\frac{1}{6^3} -\frac{1}{1^3})$
$=-\frac{1}{3}(\frac{1}{216} -1)$
$=-\frac{1}{3}(-\frac{215}{216})$
$=\frac{215}{648}$