Having problems with this triple integral

I'm trying to solve this problem. Here's my code:

%44
fun = @(x,y,z) 1./(x.^2 + y.^2);

xmin = -1;
xmax = 1;
ymin = 0;
ymax = @(x) sqrt(1-x.^2);
zmin = 0;
zmax = @(x,y) y;
q= integral3(fun,xmin,xmax,ymin,ymax,zmin,zmax)

and this runs into and error saying that it reached the maximum number of function evalutions and failed the global error test. Can anyone tell me what did I do wrong?

Answer 1

[Bianca Drumea]

Are you missing a semicolon on the final line?

Answer 2

[Carlos Guerrero García]

The exercise ask for the evaluation using cylindrical coordinates and you're not using cylindrical coordinates in your code. Also, note that the origin belongs to Omega but the function 1/(x^2+y^2) is undefined in that point (i.e. you've got an improper integral right there)

Also, notice that your code works fine (although without cylindrical coordinates) changing "ymin=0" with "ymin=0.1", or "ymin=0.01", or "ymin=0.001", or "ymin=0.0001", ...

What do you think about the limit when "y" tends to cero?