MATLAB: How to solve multiple equations dependent on each other

dependent on each other

Hi
How to code this situation?
I have two equations, which are dependent on each other. Y=2X+5—-(1) and X=2Y+5—–(2) The initial value of X=1, then I have to solve these equation repeatedly for 10 times.
Thanks

Best Answer

  • Since you depend on your previous answers, you can simply loop through the equations and store the answers.
    x = ones(1,10); % also contains your initial x
    y = ones(1,10); % just to preallocate y as well
    for i=1:9 % loop 9 times
    y(i) = 2*x(i) + 5; % calculate the y-value

    x(i+1) = 2*y(i) + 5; % calculate the 'next' x-value

    end
    y(10) = 2*x(10) + 5; % finish off by calculating the final y-value
    If you only care about the final value, this suffices:
    x = 1;
    for i=1:9
    y = 2*x + 5; % calculate the y-value
    x = 2*y + 5; % calculate the 'next' x-value
    end
    y = 2*x + 5;