Minimizing expected value using a multivariate normal distribution

I am trying to minimise the expected value of this function w.r.t the variable Q :

where f(D) is the probability density function of a multivariate normal distribution,c0 and cu parameters.

This is what I have done so far :

    syms X1

    syms X2

    syms X3

    c0 = 1 ;

    cu = 1 ;

    x = [X1; X2; X3] ;

    mu = [3; 5; 7 ] ;

    sigma = [4,3,6;3,8,5;6,5,10] ;

    s = mvnpdf(x,mu,sigma) 

    syms Q

    syms D

    f = (Q-D).*s ;

    z = c0.*int(f,D,0,Q) ;

    anon_z = matlabFunction(z) ;

    g = (D-Q).*s ;

    t = cu.*int(g,D,Q,inf) ;

    anon_t = matlabFunction(t) ;

    tot = @(Q) anon_z(Q) + anon_t(Q) ;

    [x fx] = fminsearch(tot,0)

It gives me this errors :

    Error in
    symengine>@(Q,X1,X2,X3)Q.^2.*exp(conj(X1).*conj(X3).*(3.0./2.0)).*exp(conj(X2).*conj(X3).*(1.0./1.1e1)).*exp(conj(X1).*-3.0).*exp(conj(X2).*(3.0./1.1e1)).*exp(conj(X3).*(2.6e1./1.1e1)).*exp(conj(X1).^2.*(-5.0./4.0)).*exp(conj(X2).^2.*(-1.0./1.1e1)).*exp(conj(X3).^2.*(-2.3e1./4.4e1)).*exp(-8.75688228083863).*(1.0./2.0)

    Error in @(Q)anon_z(Q)+anon_t(Q)

    Error in fminsearch (line 189)
    fv(:,1) = funfcn(x,varargin{:});

    Error in multi_3giocatori (line 19)
    [x fx] = fminsearch(tot,0)

can you help me fix this?