MATLAB: Help, secant method by recursion

Question

I'm trying to write a function that uses the secant method to find a root of the function.

I'm required to write both the iterative and recursive method.

So far, I finished writing the iterative but cannot finish the recursive.

The iterative is

function root = secanti(n, x0, x1, err)
while true
  xi = (x0 * feval(n,x1) - x1 * feval(n, x0))/(feval(n,x1) - feval(n,x0));
  if abs((xi-x1)/xi) < err
      root = xi;
      break
  else
      x0 = x1;
      x1 = xi;
  end
end
end

The one I have for recursive so far is

function xi = secantr(n, x0, x1, err)
 xi = (x0 * feval(n,x1) - x1 * feval(n, x0))/(feval(n,x1) - feval(n,x0));
if abs((xi-x1)/xi) < err
    return
end
x0 = x1;
x1 = xi;
secantr(n,x0,x1,err)
end

The recursive function keeps giving a different value from the iterative.

Is there any way to improve my recursive function? Thank you

Answer 1

All you need is to catch the output:

xi = secantr(n,x0,x1,err);
^^^^