How to Determine and Visualize Integration Limits in 3D Surfaces?

Click For Summary
To determine the limits of integration for the volume between the surfaces z = 3 - 2y and z = x^2 + y^2, set the equations equal to find their intersection in the xy-plane. Visualizing the surfaces is crucial; one is a plane and the other is a paraboloid. If the problem does not specify the relationship between the surfaces, plotting them can help clarify which is above the other. Drawing a 3D representation can significantly aid in understanding their spatial relationship. Proper visualization is key to solving integration problems involving 3D surfaces.
BrownianMan
Messages
133
Reaction score
0
Find the volume lying below z = 3 - 2y and above z = x^2 + y^2.

How would I go about finding the limits of integration for this problem?
 
Physics news on Phys.org
Set the z's equal and plot the resulting xy equation in the xy plane to figure out the limits.
 
Thanks.

What if the question did not specify that z = 3 - 2y was above z = x^2 + y^2? How would I determine that it was in fact above it? I'm having some trouble visualizing all of this in 3 dimensions.
 
BrownianMan said:
Thanks.

What if the question did not specify that z = 3 - 2y was above z = x^2 + y^2? How would I determine that it was in fact above it? I'm having some trouble visualizing all of this in 3 dimensions.

The usual way to help visualize things like this is to draw a picture of the surface. You should be able to recognize one as a paraboloid and the other a plane.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

Similar threads

  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 16 ·
Replies
16
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
6
Views
2K
  • · Replies 21 ·
Replies
21
Views
3K