Question

Evaluate ${\int }_0^3$ f(x) dx if $f\left(x\right)=x^2+8x+5$

Answer 1

${\int }_0^{3}f\left(x\right)dxf\left(x\right)=x^2+8x+5{\int }_0^3{x}^2+8x+5dx{\frac{x^3}{3}+8\frac{x^2}{2}+5x|}_0^3\frac{3^3}{3}+4\left(3^2\right)+5\left(3\right)-0-0-09+36+15=60$