integration problem

[Ilya Barshai]

Ok, so I hacked out a method for integration myself with very little
direction, so I don't know if I am doing it in the most efficient
way, but here is my problem. The following integral yields complex
answers.

l = 1;
s = 0.3;
x = 0:0.02:0.3;
syms y;
for j=1:16
G3sym = (2/l) * int(((sqrt(y^2-x(1,j)^2)) / (sqrt(y^2-s^2))) *
s/y,y,s,l);
G3 = double(G3sym);
data(1,j)=G3;
end

This shouldn't yield complex numbers because upon examination, there
really is no part that would. y^2 is always greater than x^2, so I
don't see where the imaginary part is coming from.

Is there something wrong with my notation?
Am I misunderstanding this mathematically?

I really need to find the answer to this problem. I have spent quite
a while trying to figure it out and would really appreciate any
input.

Thanks