Finding the area between curves

In summary, the conversation is discussing the intersection points of two curves, y = x^5 - 2ln(x+5) and y = x^3 - 2ln(x+5), and determining the limits of integration for the required integral. The participants mention potential intersection points at x = 0, 1, and -1, and suggest using the equation y = x^5- 2ln(x+5)= x^3- 2ln(x+5) to solve for the intersection points.
  • #1
rayray19
17
0

Homework Statement



y = x^5 - 2ln(x+5)

and

y = x^3 - 2ln(x+5)


Homework Equations





The Attempt at a Solution



i put it ont he calculator but i honestly don't even no where the spot that i amtrying to find the area for is
 
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  • #2
well find where they intersect and you will find the limits of the required integral
 
  • #3
they intersect at x = 9.24?
 
  • #4
They also pretty clearly intersect at 0.
 
  • #5
ok so now how do i get started with that
 
  • #6
Actually, I wasn't paying attention. How did you get 9.24 as an intersection point? They intersect at x = 0 and x = 1. Those are the limits of integration that are desired I imagine.
 
  • #7
yea i don't even no where the 9.24 came from.. so i do it from x=0 to x=1 and what is the top and bottom values??
 
  • #8
Uh, I didn't sketch the graph when I did this, but isn't x=-1 also a possible intersection point?
 
  • #9
One of the very first things you should have learned is that two curves intersect where the same x-value gives the same y-value.

The graphs of y = x^5 - 2ln(x+5) and y = x^3 - 2ln(x+5) intersect where
y= x^5- 2ln(x+5)= x^3- 2ln(x+5). Can you solve that equation?
 

FAQ: Finding the area between curves

What is the concept of finding the area between curves?

The concept of finding the area between curves involves calculating the area enclosed by two curves on a graph. This is typically done by finding the points of intersection between the curves and using integration to find the area between those points.

How is the area between curves calculated using integration?

The area between curves is calculated using integration by finding the definite integral of the difference between the two functions. This means taking the integral of the upper curve minus the integral of the lower curve between the points of intersection.

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 regions. This means that the area is being "subtracted" instead of "added" in the integration process.

Are there any special cases when finding the area between curves?

Yes, there are a few special cases when finding the area between curves. One is when the curves intersect at more than two points, in which case the area between the curves must be calculated in separate parts. Another is when the curves do not intersect at all, in which case the area between them is simply the integral of the difference between the two functions over the entire domain.

How is finding the area between curves useful in real-world applications?

Finding the area between curves can be useful in many real-world applications, such as in calculating the area under a pressure vs. volume curve in thermodynamics or in determining the area between supply and demand curves in economics. It can also be used to find the area of irregular shapes on a graph.

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