Write a quadratic equation function

Hi all,

I've been writing a function to solve a quadratic equation of the form ax^2 + bx + c. It works for quadratics where there are two real roots, but I want it to display NA for one of the roots when there is a repeated root or NA for both when there are no real roots. Not sure if I have to use an if statement or an if else statement?

Thanks for any help!

Answer 1

[Honglei Chen]

Isn't this just depending on the value of b^2-4*a*c, something like

val = b^2-4*a*c;
if val > 0
  % two roots
elseif val == 0
  % one root, one NA
else
  % NA
end

[Sam]

Yeah, I'm just having trouble getting NA displayed in the command window when I run it from there. Eg for x^2 - 6x + 9,

x1 = 3, x2 = NA

Thank you

[Sam]

I've got it now, Thank you!