Question

Solve
${\int }_{10}^{13}2xdx$

Answer 1

We have

$I=\underset{10}{\overset{13}{\int }}2xdx$

$={\left[2\times \frac{x^2}{2}\right]}_{10}^{13}$

$={\left[x^2\right]}_{10}^{13}$

$={\left(13\right)}^2-{\left(10\right)}^2$

$169-100$

$=69$

Hence,

$\underset{10}{\overset{13}{\int }}2xdx=69$