I have this:

-6+Sqrt 6^2 - 4*1*6

2*1

so following this through i ended up at:

-3+Sqrt 6

but the answer in my book is saying i should have the square root of 3.

How does square root of 12 divided by 2 end up as square root of 3 instead of 6 (12/2)??

probably really simple but after reading about eigenvalues and dynamic matrix for the last hour my heads just hurts......