Find all zeros of quartic function

[needmathhelp]

Homework Statement

Need help finding all zeros of this quartic function. Can someone show the work involved in solving the following equation?

Homework Equations

f(x)=x^4-x^3-5x^2-x-6

The Attempt at a Solution

 

[Clever-Name]

Sorry, that's not how it works here. We won't just do the work for you, if you post what you have done and where you are stuck then we can give you some guidance as to how to proceed.