# Math Help - line of symmetry of a function

1. ## line of symmetry of a function

what is the equation of the axis of symmetry for this function?
y = ( x-3)(x-7)

2. Originally Posted by ecdino2
what is the equation of the axis of symmetry for this function?
y = ( x-3)(x-7)
For parabolic equations this is always through the vertex. When the equation is in intecept form the vertex is always the midpoint of the x-intercepts.

So for the above the vertical line is x=...

3. Originally Posted by ecdino2
what is the equation of the axis of symmetry for this function?
y = ( x-3)(x-7)
It's half way inbetween our zeros. So,

$x_{sym} = \frac{ 7 + 3 }{2} = 5$