SOLUTION: Tell whether the graph opens up or down. Find the coordinates of the vertex. Write an equation of the axis of symmetry. y=-9x(to the 2nd power) I don't know how to type to the 2

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Question 2128: Tell whether the graph opens up or down. Find the coordinates of the vertex. Write an equation of the axis of symmetry.
y=-9x(to the 2nd power) I don't know how to type to the 2nd power on the computer
Answer by matthew_sessoms(39) (Show Source):
You can put this solution on YOUR website!

Anytime the x^2 term is a negative it is going to open down. Anytime the x^2 term is positive it is going to open up.
So, this parabola opens down.

Since there is only 1 term, which is 9x^2, we really can't complete the square. However, we could say . This is in the form of y=a(x-h)^2+k, where (h,k) is the vertex and x=h is the axis of symmetry.

So, (0,0) is the vertex...
x=0 is the axis of symmetry.

Here is the graph to prove my statements...

MS