How to solve this problem that says "error".

hi guys... I have a problem that this code doesn't work saying error..( I want to Integral like this..) All variables are defined. and 'j' is the imaginary unit. Please help me .. Thanks for reading ...

diC1= (((2*pi*e0)*((R^2)*(1-sin(th)))/((z)*(z)+R*sin(th))));

Call1= 2*pi*e0*R*log(1+R*(1-sin(th))/z)+C00;

Re1= ((diC1)*(j/(2*pi*f*(Call1).^2))*(yab/((1+yaa*Rs)*(1+ybb*ZL)-(yab)^2*Rs*ZL))...
  -yab*ZL*(ybb+yaa*ybb*Rs-yab^2*Rs)/((1+yaa*Rs)*(1+ybb*ZL)-yab^2*Rs*ZL)^2);%*(z(i)-z0);

Re11= int(Re1);

z=0e-9:0.01e-9:100e-9;

plot(z,Re11)

[Adam]

Closed as being a duplicate of:

https://uk.mathworks.com/matlabcentral/answers/330145-i-don-t-understand-why-this-code-doesn-t-work-error