Without using the roots command, write a function to calculate roots of the quadratic equation

8 次查看（过去 30 天）
Chris
Chris 2013-6-24
Without using the roots command, write a function to calculate roots of the quadratic equation
ax^2+bx+c=0
Inputs to the function should be the coefficients a, b and c and output should be the roots. Test your program by setting a=2,b=3,c=-1
can someone help me out with this? I cant think of anything but roots to use. would I have to use poly? or fzero?

请先登录，再回答此问题。

采纳的回答

Evan
Evan 2013-6-24
No need to call any built-in function. Just write your own using the quadratic formula.

更多回答（2 个）

Tom
Tom 2013-6-24
I'd recommend maths.
James Tursa
James Tursa 2013-6-24
You can use one of the formulations here:
http://en.wikipedia.org/wiki/Quadratic_equation
The quadratic formula is listed, of course, but that is prone to cancellation error. So I would advise impressing your professor by coding up the algorithm under the "Avoiding loss of significance" section.
  2 个评论
Chris
Chris 2013-6-24
This confuses me still how do I add in an Algorithm? Im terrible at this matlab stuff. so would i have to put the original function in?
James Tursa
James Tursa 2013-6-25
It would be best if you could post what you have so far and then we can comment on it and suggest improvements. E.g., a function outline would be this (e.g., put in a file called quadratic_roots.m):
function [x1 x2] = quadratic_roots(a,b,c)
% add your code here to calculate x1 and x2
return
end

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 MATLAB 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by