How to solve explicit integral could not be found

I'm trying to write the function

Below is my code

q=1;
y=10;
v=3.5;
t=1;
z=v*t;

syms pi theta x1 x2

a=-(q*x1*v)/4*pi;

b=(0.5*x1)- (y*cos(theta));

c=(y.^2)+((0.5*x1).^2)+(x1*y*cos(theta));

d=z+(0.5*x2);

e=z-(0.5*x2);

f=(c+(d.^2)).^0.5;

g=(c+(e.^2)).^0.5;

h=(b/c)*((d/f)-(e/g));

i=int(h,theta,0,2*pi);

p=a*i;

However, I got warning explicit integral could not be found. x1 and x2 are the variables that I want to optimized using PSO. How can I avoid this warning because it affects my PSO output? Many thanks for your help.