Answer:

Step-by-step explanation:
The integral of a function gives you the area under the curve, the subtraction of one of the areas from the other will give you the area in between.
The limits of integration are the points where the curves intersect each other(take the curves has a system of equation and solve for x and y):


The integral will be the subtraction of the curve
and
(In the graph you can see y=3x is the upper curve):

For example, three points are always coplanar, and if the points are distinct and non-collinear, the plane they determine is unique. However, a set of four or more distinct points will, in general, not lie in a single plane. Two lines in three-dimensional space are coplanar if there is a plane that includes them both.