Answer:
13.5
Explanation:
The geometric representation of an integral is the area below the curve. So, let's graphic the function.
is an horizontal line, (y = 3)
and
is also a line, but it is decreasing.
We can see in the image that the area below the curve happens to be a polygon. In order to calculate the area we are going to separate it into simpler polygons: a square and a triangle.
The area of the square is
.
The area of the triangle is
If we add them, we get
