#### Finding Area Under a Curve

- Integration, or in exact definite integrals, are useful in finding areas under a graph.
- In this course, the total area is more of a concern compared to the signed area, if the questions requests you to find an area of a region. Therefore, it can be found using definite integrals as above, but be mindful of whether the area is above the x-axis, below, or mixed.
- In the following, consider the function f(x) and the area A of the region contained by the curve, the axis and the range x\in[a,b].

i) If f(x)\geq0 for all x\in[a,b], then we have

A=\int_{a}^{b} f(x) d x