Is My Solution for the Triple Integral Correct?

Click For Summary

Homework Help Overview

The discussion revolves around the evaluation of a triple integral given by the original poster, which involves integrating the expression \(y + 2x^2z\) over specified limits. Participants are examining the correctness of the computed results and the methods used for integration.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • Some participants provide their computed results, with one using Maple to arrive at \(\frac{32}{21}\) and others confirming this result through manual calculations. The original poster expresses uncertainty about their own result of \(\frac{59}{36}\) and seeks verification.

Discussion Status

Multiple participants have shared their results, with at least two confirming the value of \(\frac{32}{21}\) through manual integration. The original poster's result remains unverified, and there is an ongoing exploration of the integration process.

Contextual Notes

The original poster mentions the difficulty of presenting their solution in LaTeX format, which may impact the clarity of their approach. There is also a light-hearted acknowledgment of the challenges involved in performing the calculations by hand.

mathzeroh
Messages
98
Reaction score
0
Triple Integral Evaluation (quick and easy)

Homework Statement


[itex] \int_{0}^{1} \int_{x^2}^{1} \int_{0}^{3y} ({y+2x^2z})dz dy dx[/itex]


Homework Equations



None.

The Attempt at a Solution



Here is what I got at the end (the LaTeX takes too long to code in here, plus its not showing up):

59/36 because after integrating the whole thing, and then putting in the very last limits (0 and 1), all of the x's go away leaving just the coefficients which I worked out to get 59/36...can someone please verify this for me? I've checked it twice and got the same solution..it takes about 3 minutes to do if you're a genious (unlike me, so I'm trying to appeal to the math geniuses)..

thanks!
 
Last edited:
Physics news on Phys.org
I get (actually Maple) [itex]\frac{32}{21}[/itex]

∫{0}^{3y}(y+2x²z)dz= 9x²y²+3y²

∫_{x²}^{1}( 9x²y²+3y²)dy= -3x^{8}-x^{6}+3x²+1



∫_{0}^{1}(-3x^{8}-x^{6}+3x²+1) dx= ((32)/(21))
 
did it by hand and got 32/21
 
I did it by hand, too. :-p I had to type everything and then use the "ctrl c-ctrl v" keys. It's not as easy as it seems...:biggrin:

Daniel.
 
[tex]\int_0^1\int_{x^2}^1\int_0^3y (y+ 2x^2z)dzdydx[/tex]
[tex]\int_0^1\int_{x^2}^1\left[yz+ x^2z^2\right]_0^{3y}dydx[/tex]
[tex]3\int_0^1\int_{x^2}^1(1+ x^2)y^2 dy dx[/tex]
[tex]\int_0^1\left[(1+3x^2)y^3\right]_{x^2}^1 dx[/tex]
[tex]\int_0^1(1+3x^2)(1-x^6)dx[/tex]
[tex]\int_0^1(-3x^8- x^6+ 3x^2+ 1)dx[/tex]
[tex]\left[-\frac{1}{3}x^9-\frac{1}{7}x^7+ x^3+ x\right]_0^1[/tex]
[tex]-\frac{1}{3}-\frac{1}{7}+ 1+ 1[/tex]
[tex]-\frac{7}{21}-\frac{3}{21}+\frac{21}{21}+\frac{21}{21}[/tex]
[tex]\frac{32}{21}[/tex]
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 9 ·
Replies
9
Views
3K
Replies
4
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
2
Views
1K
Replies
6
Views
2K
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
3K
Replies
1
Views
2K