Error: Not Enough Input Arguments

"Error using quadroot (line 2). Not enough input arguments" why does it give me this error message? here is my code:

 function [x] = quadroot(a,b,c)
  if a==0
      %special cases
      if b ~= 0
          %single root
          x1 = -c/b;
      else
          %trivial solution
          disp('Trivial solution.')
      end
  else
      %quadratic equatioon
      d  = b^2 - 4*a*c;
      if d>=0
          x1 = (-b + sqrt(d))/(2*a);
          x2 = (-b - sqrt(d))/(2*a);
      else
          x1 = -b/(2*a);
          i1 = sqrt(abs(d))/(2*a);
          x2 = x1;
      end
  end

Answer 1

[Image Analyst]

Because when you called it, or ran it if this is an m-file, you did not supply a, b, and c.

Answer 2

[Dr. Seis]

A couple of questions:

1. How are you running this? If you are trying to run this from the Editor, then you will be running it without defining a, b or c.

2. Is this the actual code you are using? I ask because it the output argument "x" is never defined, though "x1" and "x2" are defined. Should replace x1 with x(1) and x2 with x(2).

3. What is "i1" used for? Your 4th to last line of code you define, but never use, "i1".