Question 466574
    Hello and thank you so much for your help.I got this function 7-6x-x^2=0 it's a parabola that crosses the x-axis on the points -7.0 and 1.0, the vertex it's at the point (-3.0,16). I need to find the equation of the axis of symmetry for this parabola. Thank you again and have a happy 4th of July.
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You can derive the axis of symmetry from the vertex and "inspecting" the original equation.
First, 
Determine whether it is a "vertical" or a "horizontal" parabola.  If your equation has a x^2 term -- it is a "vertical" parabola.
Second,
Once you know this, then you can simply use the x-coordinate of the vertex.  So, the axis of symmetry is then
x = -3 (vertical line crossing the x-axis at -3)
.
Note:
the axis of symmetry is also derived by:
-b/(2a)
where
'a' and 'b' are the coefficients of the original equation