college algebraneed help Please!!!
posted by ladybug on .
I need to find the vertex and axis of symmetry of the folowing quadratic function. Can someone PLEASE help me!!
y= x^26x

You can complete the square ....
y = (x^2 + 6x +9  9
= ( (x+3)^2  9)
= (x+3)^2 + 9
vertex is (3, 9)
alternate method:
for y = ax^2 + bx + c
the x of the vertex is b/2a
for for yours
the x of the vertex is (6)/2 = 3
sub into the function ...
y = 9 + 18 = 9
so the vertex is (3,9) as above
The simplest way is to use Calculus, but I am not sure if you are studying Calculus. 
Reiny,
It seems like Calculus, but it actually falls under college algebra. Because I can get some calculus tutoring and the answers fit. Thank you for the help, it is greatlt appreciated!!!