# line of symmetry of a function

• June 6th 2010, 04:57 PM
ecdino2
line of symmetry of a function
what is the equation of the axis of symmetry for this function?
y = ( x-3)(x-7)
• June 6th 2010, 05:23 PM
TheEmptySet
Quote:

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=...
• June 6th 2010, 05:26 PM
AllanCuz
Quote:

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,

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