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y= -x^2-6x

• college algebra--need help Please!!! -

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.

• college algebra--need help Please!!! -

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!!!

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