What are the possible rational zeros of f(x) = 3x4 + x3 – 13x2 – 2x + 9?

I'm so confused I thought it was this. But it's wrong?

± 1, ±1/3 , ±1/9 , ± 3

Question

What are the possible rational zeros of f(x) = 3x4 + x3 – 13x2 – 2x + 9? 

I'm so confused I thought it was this. But it's wrong?

± 1, ±1/3 , ±1/9 , ± 3

anonymous · Answer

Nvm there's no 1/9 right?

anonymous · Answer

no

anonymous · Answer

should be $\pm9$

anonymous · Answer

>>> def f(x):
...     return 3*x**4 + x**3 - 13*x**2 -2*x + 9
... 
>>> f(-1)
0
>>> f(9)
19350
>>> f(-9)
17928

-1 is one zero

anonymous · Answer

Sorry I don't know how to factor these.  The only other zero I found between -100 and 100 by computation is near 1.78.

anonymous · Answer

You might want to check your equation again.  I'm sure that one root is -1, the others seem to be near 1.78, -1.969, and 0.856.  While these could be rational numbers, it doesn't seem right.