Question

where is the vertex of the graph of y=x2+6x-2?

Answer 1

complete the square:

y=x2+6x-2
= x^2 + 6x + 9 - 9 -2
= (x+3)^2 - 11

so the vertex is (-3,-11)

or

for y = ax^2 + bx + c, the x value of the vertex is -b/(2a)
sub that back in the original equation to get the y of the vertex.
x of vertex = -6/2 = -3
y = (-3)^2 + 6(-3) - 2 = -11