Area between Curves: Find the Bounded Region

In summary: Then, as HallsofIvy suggests, one should proceed to find the intersection points and set up the integral. In summary, the problem is to find the area bounded by the curves x = 4 - y^2 and x = y^2 - 2y, which can be solved by graphing the two equations, finding the intersection points, and setting up the integral using the appropriate area element. The fact that y is the dependent variable rather than x does not affect the process.
  • #1
flyers
29
0

Homework Statement



Find the area bounded by the curves given by the graphs x = 4 - y^2 and x = y^2 - 2y


The Attempt at a Solution



I don't know how I can integrate these curves as they are not functions. Can someone tell me to get started on this problem?

Thank you
 
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  • #2
flyers said:

Homework Statement



Find the area bounded by the curves given by the graphs x = 4 - y^2 and x = y^2 - 2y


The Attempt at a Solution



I don't know how I can integrate these curves as they are not functions. Can someone tell me to get started on this problem?

Thank you

They most certainly are functions. They just don't have x as the independent variable like you're used to. It matters little, you can still get it done.

Integrating is the same no matter the variable of integration...
 
  • #3
flyers said:

Homework Statement



Find the area bounded by the curves given by the graphs x = 4 - y^2 and x = y^2 - 2y


The Attempt at a Solution



I don't know how I can integrate these curves as they are not functions. Can someone tell me to get started on this problem?

Thank you
They aren't functions, but they are curves, and they define a bounded region. Start by graphing them and finding where the two curves intersect, and then figure out what your typical area element looks like - i.e., horizontal strip of vertical strip- and its dimensions.
 
  • #4
Mark44 said:
They aren't functions, but they are curves, and they define a bounded region. Start by graphing them and finding where the two curves intersect, and then figure out what your typical area element looks like - i.e., horizontal strip of vertical strip- and its dimensions.

Actually, they are functions. They're just functions of y, not the functions of x most people are used to.
 
  • #5
you could also just solve for y with those two equations and you would have what you are use to. Just think of those as respect to the y-axis and not the x. So the region you are measuring is taking the integral of the y dy instead of x dx, still the same just a different reference.
 
  • #6
Char. Limit said:
Actually, they are functions. They're just functions of y, not the functions of x most people are used to.
True, but people generally think of functions where y is the dependent variable and x is the independent variable, out of force of habit. In that sense, the equations don't represent functions.

In any case, the important thing is that the OP should graph both equations to find the region whose area is to be found.
 

FAQ: Area between Curves: Find the Bounded Region

What is the area between curves?

The area between curves refers to the region bounded by two or more curves on a graph. This area can be found by calculating the definite integral of the difference between the two curves over a given interval.

How do you find the bounded region between two curves?

To find the bounded region between two curves, you will need to first graph the two curves and determine the points of intersection. Then, set up the integral by subtracting the lower curve from the upper curve and integrating over the interval of the points of intersection.

What is the formula for finding the area between curves?

The formula for finding the area between curves is given by the definite integral of the difference between the two curves over a given interval. This can be written as ∫(f(x) - g(x)) dx, where f(x) and g(x) are the two curves and dx represents the integration with respect to x.

Can the area between curves be negative?

Yes, the area between curves can be negative if the lower curve is above the upper curve in certain parts of the interval. This means that the definite integral will result in a negative value, indicating that the bounded region has a negative area.

What are some real-life applications of finding the area between curves?

Finding the area between curves has many real-life applications, such as calculating the total profit or loss in a business, determining the amount of material needed for a construction project, and predicting the growth or decline of a population. It can also be used in physics to calculate the work done by a varying force or to find the area under a velocity-time graph.

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