# Double Integral help

Printable View

• Nov 8th 2013, 09:55 PM
Brennox
Double Integral help
Please view the attached.

What ive done:

(-1, 2)
(1, 2) are the intercepts.

my integral has dy then dx.
1top -1bottom on the outside integral.
(x^2 + 1)top (2x^2)bottom on the inside integral.

****

So i got 8/15 units^2 just wondering if this is right, if not pls help.
• Nov 9th 2013, 02:00 PM
chiro
Re: Double Integral help
Hey Brennox.

One method for future ref erence to check symbolic calculations is to use Wolfram Alpha which is a symbolic computational engine. You should put your integral in there to see how it turns out:

Wolfram|Alpha: Computational Knowledge Engine

This is especially useful if you can't find someone quick enough.
• Nov 9th 2013, 05:43 PM
Prove It
Re: Double Integral help
Quote:

Originally Posted by Brennox
Please view the attached.

What ive done:

(-1, 2)
(1, 2) are the intercepts.

my integral has dy then dx.
1top -1bottom on the outside integral.
(x^2 + 1)top (2x^2)bottom on the inside integral.

****

So i got 8/15 units^2 just wondering if this is right, if not pls help.

I agree with your bounds. I don't agree with your final answer. Unless you post all your working, I can't see where you've gone wrong.
• Nov 10th 2013, 12:18 AM
Brennox
Re: Double Integral help
Quote:

Originally Posted by Prove It
I agree with your bounds. I don't agree with your final answer. Unless you post all your working, I can't see where you've gone wrong.

okay i got it arithmatic error, can you have a look at this other question please

http://mathhelpforum.com/calculus/22...-question.html
• Nov 10th 2013, 04:53 AM
mathnerd15
Re: Double Integral help
did you get 16/15? it's really an easy integral
• Nov 10th 2013, 05:13 PM
Prove It
Re: Double Integral help
I got 16/15 as well.
• Nov 10th 2013, 10:02 PM
Bestwebuys
Re: Double Integral help
Bài viết hay!

Ruột bút Montblanc chính hãng tại Việt Nam - 400 Trần Hưng Đạo, P.2, Q.5, Tp.Hồ Chí Minh Thứ 2 - 7 : 8:00am - 5:30pm Các sản phẩm ruột bút Montblanc bao gồm: ballpoint, fineliner, mozart và rollerball.
• Nov 15th 2013, 02:58 PM
mathnerd15
Re: Double Integral help
I'm curious how one visualizes a 4 dimensional object for a quadruple integral where the planes are 3d surfaces- like you can it seems deduce properties of a 4D cube.
there was an interesting amplituhedron discovery lately in 4 dimensions