Could not solve 2 equations using the MATLAB.

I have to solve two equations using MATLAB. For this, i have taken the equations as the following :

syms x y eq1 eq2;

eq1 = x^7 + 42.215449*x^6*y + 287.89234 *x^6 + 596.846934 * x^5*y^2 + 8742*x^5*y + 28324*x^5 + 2043*x^4*y^3 + 43094*x^4*y^2 + 266735*x^4*y + 498519*x^4 + 288.63823*x^3*y^4 + 33339*x^3*y^3 + 520794*x^3*y^2 + 2476074*x^3*y + 3223591*x^3 - 208.79156*x^2*y^5 + 6073*x^2*y^4 + 234014*x^2*y^3 + 2220025*x^2*y^2 + 7793982*x^2*y + 8129372*x^2 - 52.07952*x*y^6 + 104.05264*x*y^5 + 35721*x*y^4 + 555238*x*y^3 + 3446089*x*y^2 + 9208694*x*y + 8083970*x - 3.07772*y^7 - 21.7637*y^6 + 1870*y^5 + 42024*y^4 + 374588*y^3 + 1636383*y^2 + 3381409*y + 2510676 ;

 eq2 = x^7 + 42.35951*x^6*y + 249.65506*x^6 + 384.45864*x^5*y^2 + 3593*x^5*y + 6262*x^5 + 820.0502*x^4*y^3 + 11020*x^4*y^2 + 42458*x^4*y + 42460*x^4 - 190.762*x^3*y^4 + 323.880*x^3*y^3 + 12187*x^3*y^2 - 14416*x^3*y - 53002*x^3 - 273.565*x^2*y^5 - 10984*x^2*y^4 - 144716*x^2*y^3 - 769764*x^2*y^2 - 1669218*x^2*y - 1214524*x^2 - 61.9525*x*y^6 - 3876*x*y^5 - 75440*x*y^4 - 643676*x*y^3 - 2570248*x*y^2 - 4473769*x*y - 2750044*x - 4.1241*y^7 - 333.6706*y^6 - 8419*y^5 - 99085*y^4 - 607023*y^3 - 1930062*y^2 - 2885924*y - 1593986;

I tried to solve for the x & y values using the command : SS = solve(eq1, eq2) But, even after waiting for 6 hours also, it did not give any out put.

I tried to use even fsolve also for solving the eq1 & eq2 equations. But, because of not giving the initial guess properly, Matlab is not giving the correct outputs.

Can anyone please help me in trying to solve these equations? I am desperate for the answer.

Answer 1

[David Sanchez]

No need of symbolic calculus. Apdapt the example to your equations:

This example solves the system of two equations and two unknowns:

Rewrite the equations in the form F(x) = 0:

Start your search for a solution at x0 = [-5 -5].

First, write a file that computes F, the values of the equations at x ( in your case x = x(1) and y = x(2) ) .

function F = myfun(x)
F = [2*x(1) - x(2) - exp(-x(1));
      -x(1) + 2*x(2) - exp(-x(2))];

Save this function file as myfun.m somewhere on your MATLAB path.

Next, set up the initial point and options and call fsolve:

x0 = [-5; -5];           % Make a starting guess at the solution
options=optimset('Display','iter');   % Option to display output
[x,fval] = fsolve(@myfun,x0,options)  % Call solver

[kalpana]

Thank you for your answer. But, i made some initial guesses and used fsolve function to get the solution for the equations. But, i did not get the correct answer because of wrong initial guesses.

Can you please tell me how to get the initial guess for the fsolve function ?

Thank you once again for your answer.