How do i input this on MATLAB

How can i input x^3+px+q=0 on MATLAB and find x in terms of p & q?

[Image Analyst]

Original question in case he edits this one away:

How can i input x^3+px+q=0 on MATLAB and find x in terms of p & q?

Answer 1

[John D'Errico]

Assuming that p and q are real numbers, do you understand there will ALWAYS be three solutions to the problem, and that for many values of p and q, exactly two of those solutions will be complex valued?

cubicroots = @(p,q) roots([1 0 p q]);

format long
cubicroots(2,3)

ans = 
  0.500000000000000 + 1.658312395177701i
  0.500000000000000 - 1.658312395177701i
 -1.000000000000000 + 0.000000000000000i