Answer
$\int_{1}^{4}(-x^2+5x+3)dx$
Work Step by Step
The area under the graph of the function $f(x)$ can be expressed as: $\int_{a}^{b}f(x)dx$, when $f(x)\geq0$ on an interval $[a,b]$.
As depicted in the graph, we see that our required area is:
$\int_{1}^{4}(-x^2+5x+3)dx$.
