Why it says undefined variable x2

function [x2] = secant(f, x0, x1)

   while true
          x2 =f(x1)*(x2-x0)/f(x0)+x1;

          if x1 == x2
              return;
          end

          x0 = x1;
          x1 = x2;
      end
  end

Answer 1

[James Tursa]

You have x2 appearing on the right hand side of your first assignment, before it has been defined.

[Dandan Lv]

thank you so much

[Hazel]

Hello @Dandan Lv, have you figured out this x2 equation that does not contain x2 on the RHS?

[Torsten]

Set n = 2 in the first formula on

https://en.wikipedia.org/wiki/Secant_method