- #1
Math10
- 301
- 0
Homework Statement
How to integrate the double integral cos(x+y) dy dx from 0 to pi and from 0 to pi again.
Homework Equations
The answer is -4.
The Attempt at a Solution
Here's the work:
u=x+y
du=dy
cos(u)du=sin(x+y)
integral of [sin(x+y)] evaluate from 0 to pi dx from 0 to pi
integral of (sin(x+pi)-sin(x))dx from 0 to pi
And what's next?