Area Between Two Functions and the Y-Axis: How to Compute the Integral?

In summary, the problem is asking to find the area enclosed by the curves y = x^2 - 6 and y = 6 - x^3, along the y-axis. To do this, you must first solve for x in terms of y for both equations. Then, find the interception point of the two functions, which is y = -2. Finally, you can integrate from x = 0 to the point of interception to find the area between the two curves.
  • #1
physicsernaw
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0

Homework Statement


Compute the area as an integral along the y-axis:
f(x) = x^2 - 6, g(x) = 6 - x^3

Homework Equations


N/A

The Attempt at a Solution



I solve for x in terms of y for both equations and end up with:
f(y) = +/-√(y+6), g(y) = (6-y)^(1/3)

I then look for interception points of the functions f(y) = g(y)
and I find y = -2.

My question is, if there is only one interception point how can I compute the area
between these two functions? I tried plugging into wolfram, and even it says
"cannot compute integral".

Am I reading the problem wrong? Or am I doing something wrong?

EDIT: When the question states "along the y-axis" does it perhaps mean the line x = 0 as a lower bound?
And then to just integrate from x = 0 to the point of interception (2)? That's the only way I can think of doing this.
 
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  • #2
You are right when you say it means to take x=0 as a lower bound, at least that would make the most sense according to the problem statement.
 
  • #3
Does the problem say something to the effect of the area bounded by the functions, f(x), g(x), and the y axis?
 
  • #4
I find this question peculiar as the graphs ##f(y)## and ##g(y)## will intersect at ##(-2,2)##. This creates two different regions ( areas to compute ) in the second quadrant bounded by the line ##x=0##.

Is there more to this problem at all?
 
  • #5
Yeah, it would be helpful to see EXACTLY what the problem says.
 
  • #6
Verbatim:

"In Exercises 27-44, sketch the region enclosed by the curves and compute its area as an integral along the x- or y-axis."

...

28). y = x^2 - 6, y = 6 - x^3, y-axis
 
  • #7
Ok, yes that says the region bounded by those two curves and the y axis, its not saying that you have to integrate with respect to y, however it would make the problem easier.
 
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What is integration along the y axis?

Integration along the y axis is a mathematical process of finding the area under a curve in the y direction. It is also known as definite integration or Riemann integration.

Why is integration along the y axis important?

Integration along the y axis is important because it allows us to calculate the total area or volume of irregularly shaped objects. It is also a fundamental concept in calculus and is used in various fields such as physics, engineering, and economics.

How is integration along the y axis different from integration along the x axis?

The main difference between integration along the y axis and integration along the x axis is the direction in which the area is calculated. Integration along the y axis calculates the area under a curve in the vertical direction, while integration along the x axis calculates the area in the horizontal direction.

What is the process of integration along the y axis?

The process of integration along the y axis involves dividing the area under the curve into small rectangles, calculating the area of each rectangle, and then summing up all the areas to get the total area. This is represented by the definite integral ∫ab f(x)dx, where f(x) is the function and a and b are the limits of integration in the y direction.

What are the applications of integration along the y axis?

Integration along the y axis has many applications in real-world problems, such as calculating the volume of irregularly shaped objects, determining the center of mass, finding the average value of a function, and solving optimization problems. It is also used in physics to calculate work and in economics to measure consumer surplus.

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