- #1
chexmix
- 8
- 0
Good day, all:
We recently hit double/triple integrals in my multivariable calculus course and I have found that my integration abilities are, well, *beyond* rusty ... and so the problem below, which is one of the very first on my current problem set, has me stumped.
[itex]\int\int_{R}\frac{x}{1+xy} dA[/itex] R = { [0,1]x[0,1] = {(x,y): 0 [itex]\leq[/itex] x [itex]\leq[/itex]1, 0 [itex]\leq[/itex] y [itex]\leq[/itex]1 }
My first and nearly only step was to turn this into an iterated integral:
[itex]\int^{1}_{0}\int^{1}_{0}\frac{x}{1+xy} dx dy[/itex]
... and this is where I begin to choke and sputter. I have started to try u-substitution on this with u = 1+xy, but didn't get anything that made sense to me; some hints I have found online seem to indicate that I should be able to perform "polynomial long division" to turn this into a sum or difference of two simpler integrals, but I guess I don't sufficiently understand polynomial long division to carry this out here.
Any hints would be much appreciated. I am considering dropping this course, but I would like to avoid that ... I need some serious integration mojo to be directly infused into my skull asap.
Regards,
Glenn
We recently hit double/triple integrals in my multivariable calculus course and I have found that my integration abilities are, well, *beyond* rusty ... and so the problem below, which is one of the very first on my current problem set, has me stumped.
Homework Statement
[itex]\int\int_{R}\frac{x}{1+xy} dA[/itex] R = { [0,1]x[0,1] = {(x,y): 0 [itex]\leq[/itex] x [itex]\leq[/itex]1, 0 [itex]\leq[/itex] y [itex]\leq[/itex]1 }
The Attempt at a Solution
My first and nearly only step was to turn this into an iterated integral:
[itex]\int^{1}_{0}\int^{1}_{0}\frac{x}{1+xy} dx dy[/itex]
... and this is where I begin to choke and sputter. I have started to try u-substitution on this with u = 1+xy, but didn't get anything that made sense to me; some hints I have found online seem to indicate that I should be able to perform "polynomial long division" to turn this into a sum or difference of two simpler integrals, but I guess I don't sufficiently understand polynomial long division to carry this out here.
Any hints would be much appreciated. I am considering dropping this course, but I would like to avoid that ... I need some serious integration mojo to be directly infused into my skull asap.
Regards,
Glenn