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Name: ____________________________________________ Date: _________________ Period: __________
Section 7.1: Area of a Region Between Two Curves
With a slight modification, we can change the concept of finding the area of a region under a curve to finding the area of a
region between two curves.
Consider the following graphs of ( )y f x and ( )y g x that are continuous on the interval 2,4 .
4
2
( ) ( )f x g x dx
4
2
( )f x dx
4
2
( )g x dx
Example 1: Finding the Area of a Region Between Curves.
Find the area of the region bounded by the graphs of 2 2, , 0 and 1. y x y x x x
Sketch the graph and shade the region.
x
y
Area of region
between f and g
Area of region
under f = Area of region
under g _
_ =
Area of a Region Between Two Curves If f and g are continuous on [a, b] and ( ) ( )g x f x for all x in [a, b], then the area of the region bounded by the graphs
of f and g and the vertical lines x a and x b is
( ) ( )b
a
A f x g x dx
x
y
x
y
-1 1 2 3
-1
1
2
3
x
y
Example 2: A Region Lying Between Two Intersecting Graphs.
Find the area of the region bounded by the graphs of 2( ) 2 and ( ) . f x x g x x
Sketch the graph and shade the region.
Example 3: A Region Lying Between Two Intersecting Graphs.
Find the area of one of the regions bounded by the graphs of ( ) sin and ( ) cos . f x x g x x
Sketch the graph and shade the region.
-2 -1 1 2
-2
-1
1
2
x
y
x
y
Example 4: Curves That Intersect at More Than Two Points.
Find the area of the regions bounded by the graphs of 3 2 2( ) 3 10 and ( ) 2 . f x x x x g x x x
Sketch the graph and shade the region.
Example 5: Horizontal Representative Rectangles.
Find the area of the region bounded by the graphs of 23 and 1. x y x y
Sketch the graph and shade the region.
x
y
x
y