Error using integral function

I am trying to get the integral of a function defined at the bottom

clear
close all
clc
 
s = -2000:10:5000;
r = -2000:10:5000;
 
%S Parameters
means = 2000;
deltas = 0.3;
SDs = means*deltas;
alphas = pi/sqrt(6)/SDs;
sigmas = 1/alphas;
mus = means - (double(eulergamma)*sigmas);
%R Parameters
CSF = 1.5;
meanr = CSF*means;
deltar = 0.2;
SDr = meanr*deltar;
alphar = pi/sqrt(6)/SDr;
sigmar = 1/alphar;
mur = meanr - (double(eulergamma)*sigmar);
syms u k
[sol_u, sol_k] = vpasolve([u*gamma(1+(1/k)) == CSF*means, u*sqrt(gamma(1+(2/k))-(gamma(1+(1/k)))^2) == meanr*deltar], [u, k]);
u = sol_u; k = sol_k;
 
%PDF Def
spdf = evpdf(s,mus,sigmas);
rpdf = wblpdf(r,u,k);
%CDF Def
%scdf = evcdf(s,mus,sigmas);
%rcdf = evcdf(r,u,k);
 
plot(s,spdf)
hold on
plot(r,rpdf)
    
syms x
Frfs = @(x) ( 1 - exp(-(x/u).^k)).*(alphas.*exp((-alphas.*(x-mus))-exp((-alphas.*(x-mus)))));
pF = integral(Frfs,0,Inf)

But I am getting an error like this

Error using integralCalc/finalInputChecks (line 522)

Input function must return 'double' or 'single' values. Found 'sym'.

Error in integralCalc/iterateScalarValued (line 315)

finalInputChecks(x,fx);

Error in integralCalc/vadapt (line 132)

[q,errbnd] = iterateScalarValued(u,tinterval,pathlen);

Error in integralCalc (line 83)

[q,errbnd] = vadapt(@AToInfInvTransform,interval);

Error in integral (line 88)

Q = integralCalc(fun,a,b,opstruct);

Error in Problem3 (line 41)

pF = integral(Frfs,0,Inf)

Answer 1

[Walter Roberson]

u = double(sol_u); k = double(sol_k);

[Maitreya Manoj Kurumbhati]

Thank you so much!