Roman C. answered 02/27/13
Masters of Education Graduate with Mathematics Expertise
To do this, we need to complete the square.
For a complete square, the constant coefficient must be (6/2)2 = 9. We get
y=x2 + 6x + 2 = x2 + 6x + 9 - 7 = (x+3)2 - 7
This is of the vertex form y = a(x - h)2 + k with vertex at (h,k) = (-3,-7)