• Support PF! Buy your school textbooks, materials and every day products Here!

Double integral help

  • Thread starter eckiller
  • Start date
  • #1
44
0
doubleIntegral( |cos(x+y)| dx dy ) over the rectangle [0, pi]x[0,pi]

I tried several ways to split the integral up so that I could remove the absolute value sign and integrate. However, I did not get the correct answer, so I must be splitting it wrong. Can someone show me how to split the region of integration up so I can integrate iteratively?
 

Answers and Replies

  • #2
489
0
At a glance, not saying this will work, but try using polar coordinates? ie x^2+Y^2=r^2 and so on.
 
  • #3
Dick
Science Advisor
Homework Helper
26,258
618
At a glance, not saying this will work, but try using polar coordinates? ie x^2+Y^2=r^2 and so on.
Polar coordinates are a bad idea. Cut the square along the lines x+y=pi/2 and x+y=(3*pi/2) - since this is where the cos changes sign.
 

Related Threads for: Double integral help

  • Last Post
Replies
14
Views
2K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
4
Views
753
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
5
Views
1K
  • Last Post
Replies
1
Views
5K
  • Last Post
Replies
6
Views
695
  • Last Post
Replies
2
Views
871
Top