>>root([1 -1 -2]) for a polynomial is not working.

It returns

"Undefined function 'root' for input arguments of type 'double'."

I also tried

>> c = [3 -2 1 2 0 -1];
roots(c)

which returned

"Attempt to execute SCRIPT roots as a function:
C:\Users\Christi\Documents\MATLAB\roots.m"

Answer 1

[Adam]

There is no 'root' function in Matlab or its toolboxes that I am aware of.

doc roots

is a function, but you have hidden it with your own script of the same name. Rename your script to something else.

In future, try to remember to do e.g.

which roots

before deciding to name your own function or variable 'roots' to check you aren't over-riding an existing function.

Answer 2

[Niels]

the first error results in a spelling mistake:

you typed root instead of roots, the second works fine:

>> c = [3 -2 1 2 0 -1]
c =
     3    -2     1     2     0    -1
>> roots(c)
ans =
   0.5911 + 0.9284i
   0.5911 - 0.9284i
   0.6234 + 0.0000i
  -0.5694 + 0.3423i
  -0.5694 - 0.3423i