- #1
8614smith
- 54
- 0
Homework Statement
[tex]I=\int^{a}_{0}dx\int^{\sqrt{a^{2}-x^{2}}_{0}[/tex][tex](x-y)dy[/tex]
Homework Equations
[tex]r^{2}=x^{2}+y^{2}[/tex]
The Attempt at a Solution
Im thinking that the question is asking to integrate the first quarter of the circle of radius a between 0 and pi/2. In that case I've changed the limits to :-
[tex]\int^{\frac{\pi}{2}}_{0}\int^{a}_{0}r.dr.d\theta[/tex] but now I am not sure what to do with the (x-y) given in the question. I can't seem to be able to rearrange this - [tex]r^{2}=x^{2}+y^{2}[/tex] to give me a value i can use in polar coordinates.
This integral apparently is supposed to give an answer of 0. is this correct? i don't see how it can be zero if there is a limit of a.