Sylva

Looks like I finally got the good result by changing the limits. Was it actually possible to do it without changing the values? I may be missing some notions that would've helped me do it...

Yes, this is the integral I'm attempting. Are you implying that I should change the limits so the limit of y depends on the value of x? This implies that I'm gonna have to integrate dx before dy. I'm not sure how this will help to resolve the problem of integrating cos[x√y] .

Hey, I've been stuck on this problem for quite some time: J = ∫0 ->4 ∫ sqrt(x) -> 2 (1 + y^2 * cos(x * sqrt(y))) dydx The cos (x * sqrt(y)) is the one causing trouble. I can't seem to find a way to integrate this. I even tried to turn it to polar coordinates but nothing seems to work. What am I doing wrong? Could someone point me in the right direction? Another thing I don't understand with multiple integrals : How do you know if it represents a Volume? Thanks in advance. PS: Sorry for my english, it's not my native language.

Hey, I've been stuck on this problem for quite some time: J = ∫0 ->4 ∫ sqrt(x) -> 2 (1 + y^2 * cos(x * sqrt(y))) dydx The cos (x * sqrt(y)) is the one causing trouble. I can't seem to find a way to integrate this. I even tried to turn it to polar coordinates but nothing seems to work. What am I doing wrong? Could someone point me in the right direction? Thanks in advance. PS: Sorry for my english, it's not my native language.