Question

Evaluate by summation method
${\int }_3^5{e}^{-8x}dx$

Answer 1

Consider the given integral.

$I={\int }_3^5{e}^{-8x}dx$

$I={\left[\frac{e^{-8x}}{-8}\right]}_3^5$

$I=[-\frac{1}{8}](e^{-40x}-e^{-24x})$

$I=\frac{1}{8}(e^{-24x}-e^{-40x})$

Hence, this is the answer.