how to solve two unknowns in two complicated eqns

Discussion in 'MATLAB' started by Yi, Apr 28, 2009.

  1. Yi

    Yi Guest

    Dear matlab friends:

    I have two very complicated eqns, like this:
    x = f(x,y)
    y = f'(x,y)
    both f and f' are very very complocated,
    for example f(x,y) = cosxy + siny +y/28*e^xy+ log(x/y^1.41)+....

    I cannot use "solve" to solve it cause it seems take forever to get the solution.

    How to write a code to solve these two eqns?

    I wrote a fix-point iteration code to solve one unknown with one eqn. But I don't know how to write a code for several unknown variables.

    Any suggestion is welcome.

    Thanks & Best Regards

    Yi, Apr 28, 2009
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  2. Yi

    Feng Guest

    what do you mean 'very very complicated'?
    the variables are x and y?
    so you get eq1: f(x,y) - x = 0; eq2: f'(x,y) - y = 0;
    if you just want to get the values of these two varialbes, try fsolve, give initial guess.
    Feng, Apr 28, 2009
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