solving a x^4 function using roots, how?

I've read about roots but I didn't quite understand it. If I have a function, how do I find the roots? By using the function roots. y = x^(4) - 2*x^(3) - 4*x^(2) - 2*x - 12

I've tried roots(y) but got the answer: >> roots(y)

ans =

Empty sym: 0-by-1

I'm not sure what it means..

Answer 1

[dbmn]

Hi Rand,

check out the documentation https://de.mathworks.com/help/matlab/ref/roots.html

it uses a certain way of notation. f.ex. for f(x) = 3x^2 -2x -4, you would use

p = [3 -2 -4];
r = roots(p)