SOLUTION: Hi, I have to find the vertex and axis of symmetry of the parabola y= -x^2+6x+3 I also have to find if it opens upward or downward. I have done this so far: a= -1 b=6 c=3 V

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: Hi, I have to find the vertex and axis of symmetry of the parabola y= -x^2+6x+3 I also have to find if it opens upward or downward. I have done this so far: a= -1 b=6 c=3 V      Log On


   



Question 52024: Hi, I have to find the vertex and axis of symmetry of the parabola
y= -x^2+6x+3
I also have to find if it opens upward or downward. I have done this so far:
a= -1 b=6 c=3
Vertex occurs when x= -b\2a = -6\2(-1) = 3
Then y=f(3)= -1(3)^2+6(3)+3
=12
Vertex (3,12).
It is downward because a<0
I am not sure on the axis of symmetry and how to work it out.
greatly appreciated if you could please help

Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
You had two small errors that were just typos, since your result came out right. The axis of symmetry is the vertical line x= 3, and the graph is like this:
graph+%28300%2C600%2C-10%2C10%2C+-20%2C20%2C+-x%5E2%2B6x%2B3%29+

R^2 at SCC