Solving Double Integrals Using U-Substitution

In summary, the conversation involved a student struggling with a homework problem that required integration by parts or substitution. The student eventually figured it out using substitution with U = xy^2.
  • #1
xtrubambinoxpr
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0

Homework Statement



Attached below

Homework Equations





The Attempt at a Solution




So I cannot figure this out. Would this be integration by parts? or by substitution.. It provides me with an answer but no reasoning behind it and I cannot figure it out =/
 

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  • #2
xtrubambinoxpr said:

Homework Statement



Attached below

Homework Equations





The Attempt at a Solution




So I cannot figure this out. Would this be integration by parts? or by substitution.. It provides me with an answer but no reasoning behind it and I cannot figure it out =/

PF rules require you to show your work. What have you tried so far?
 
  • #3
Ray Vickson said:
PF rules require you to show your work. What have you tried so far?

I had done so much work I didnt want to type it and was going to upload a picture, But indeed I figured it out.. Using U sub with U = xy^2 du = 2xy and x was a constant so it was factored out leaving everything peachy!
 
  • #4
xtrubambinoxpr said:
I had done so much work I didnt want to type it and was going to upload a picture, But indeed I figured it out..
You don't have to show us all your work - just give us some indication that you have done something.
xtrubambinoxpr said:
Using U sub with U = xy^2 du = 2xy and x was a constant so it was factored out leaving everything peachy!
 

What is double integration in Calculus 3?

Double integration in Calculus 3 is a mathematical technique used to find the volume under a three-dimensional surface. It involves integrating a function twice, once with respect to one variable and once with respect to another variable. This technique is essential in many fields such as physics, engineering, and economics.

What is the difference between single and double integration?

The main difference between single and double integration is the number of variables being integrated. Single integration involves integrating a function with respect to one variable, while double integration involves integrating a function with respect to two variables. Double integration is typically used to find the volume under a three-dimensional surface, while single integration is used to find the area under a curve in two dimensions.

What are the applications of double integration?

Double integration has various applications in fields such as physics, engineering, and economics. It is used to find the volume of irregularly shaped objects, calculate the center of mass of a three-dimensional object, and solve problems related to fluid mechanics and electricity. It is also used in economics to calculate consumer surplus and producer surplus.

What are the techniques used in double integration?

There are three main techniques used in double integration: rectangular, polar, and cylindrical coordinates. Rectangular coordinates involve integrating with respect to x and y, while polar coordinates involve integrating with respect to r and θ. Cylindrical coordinates involve integrating with respect to z and ρ. The choice of technique depends on the shape of the surface being integrated.

What are the common mistakes to avoid in double integration?

Some common mistakes to avoid in double integration include forgetting to change the limits of integration when switching between coordinate systems, forgetting to include the correct constants in the final answer, and incorrectly setting up the integral. It is also important to carefully label the variables and make sure they are consistent throughout the entire integration process.

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