solve a system of integral equations with matlab

Hi every body

I wrote the attached code to solve the integral equations written in the image.But I have a problem with matlab error

Can anyone help?

function S = Integralsystem(x,va,vb,t,xa)
x=1+int(va,t,0,t)+int(vb,t,0,t)
va=1.2*int((4/x^2-0.5/xa^2),t,0,t)
vb=(4/3)*int((3/x^2+.5/(x+xa)^2),t,0,t)
xa=70-int(va,t,0,t)
s=fsolve

Answer 1

[Torsten]

If you differentiate all your equations with respect to t, you get a system of differential equations that can be solved by standard Matlab software (like ode45, ode15s etc.).

[ALBORZ NAJAFI]

thanks a lot

I solved the problem and wrote the code

Answer 2

[Jayant Gangwar]

You need to pass the complete system of non linear equations to fsolve as input argument along with start conditions, just calling fsolve will not process anything. For information on how to pass a system of equations to fsolve please go through it's documentation, I've attached the same below

Solve system of nonlinear equations - MATLAB fsolve (mathworks.com)

Also you can take a look at the following ML answer

problem solving nonlinear equation system with fsolve - MATLAB Answers - MATLAB Central (mathworks.com)