SOLUTION: Find the axis of symmetry. y=x^2-9x-2

Algebra ->  Equations -> SOLUTION: Find the axis of symmetry. y=x^2-9x-2      Log On


   

Question 125015: Find the axis of symmetry.
y=x^2-9x-2
Found 2 solutions by jim_thompson5910, josmiceli:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
To find the axis of symmetry, use this formula:

x=-b%2F%282a%29

From the equation y=x%5E2-9x-2 we can see that a=1 and b=-9

x=%28--9%29%2F%282%2A1%29 Plug in b=-9 and a=1


x=9%2F%282%2A1%29 Negate -9 to get 9


x=%289%29%2F2 Multiply 2 and 1 to get 2


So the axis of symmetry is x=9%2F2

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
When the form is y+=+ax%5E2+%2B+bx+%2B+c the axis
of symmetry is x+=+%28-b%29+%2F+%282a%29
%28-b%29+%2F+%282a%29+=+%28-%28-9%29%29+%2F+%282%2A1%29
%28-b%29+%2F+%282a%29+=+9%2F2
x+=+9%2F2 is the axis of symmetry