Multiplying functions and syms command

So what I am trying to do is multiply two functions together then integrate it. I created a system of equations called g, and dg. I'm trying to go to the ith row of g and jth column of dg and integrate the function resulting from multiplying the separate functions together. Any suggestions?? I am very lost

for ii = 0:NRitz-1
    for jj = 0:NRitz-1
        u=matlabFunction(dg(ii+1));
        p=matlabFunction(dg(jj+1));
        m=matlabFunction(g(ii+1));
        n=matlabFunction(g(jj+1));
        syms xi
        kRitz = @(xi)Cmod*u(xi)*p(xi);
        KRitz1(ii+1,jj+1) = integral(kRitz,0,L);
    end
end

[Walter Roberson]

If you are using matlabFunction then dg and g are symbolic expressions or symbolic functions. Why not multiply them in symbolic form and use int() ?

[Paul]

Are you trying to get numerical answers to fill in KRitz1 or symbolic? The posted code suggests numerical, but maybe that's not what you want?

What is L? It is a sym or a double?

Can you post a simple, but complete code that has all relevant variables (g, dg, L) defined? Including any error messages that are of concern.

[Athul Prakash]

Can you show how you have defined g and dg? Could you also clarify what Paul has asked about above?