how to find this complex integral in matlab

Hi every one

i want to find this integral in matlab but i am getting NanN in return can anyone please help in finding this integral. Where lambda, A,a,t,N,Pj,Pk,G(a,t),H(a,t)=0,R are constant terms and Pjk^2=(Pk/Pj)^(2/a) and fy0(yo) is function of y= and equals to fy0(y0)=2y0/R^2. Wj and y0 are variables of integeration

ts = -(t*N0/P);

            cov2=@(x,y) x.*exp((ts.*(x.^(a)))-(pi*((((Ptm/Pts).^(2/(a))))+(((Pts/Pts).^(2/(a)))))).*(((a*(G(a,t)+1))+(lambdaM*(G(a,t)+1)))*(x.^2))).*(1./(1+(t.*(y./(P1.*x)).^(-a)))).*((2.*y)./(R^2));

Here is the code i tried but not working

cov22(ii) =((2*pi*lambdaS)/A2)*integral2(cov2,DistSmallcell,inf,(P2*DistSmallcell),inf)

[Arif Ullah khan]

anyone please help