# Math Help - line of relection??

1. ## line of relection??

hey guys i need your help!!

In the xy plane the equation of line L y=2x+5. If line m is the reflection of line L in the x axis what equation for m?

2. Originally Posted by fabxx
hey guys i need your help!!

In the xy plane the equation of line L y=2x+5. If line m is the reflection of line L in the x axis what equation for m?
Reflecting a function y = f(x) over the x axis gives a transformation of $y \to -y$, so your new function will be -y = f(x). Now solve for y.

So in this case we have y = 2x + 5. Reflecting this over the x axis gives -y = 2x + 5, so the line m will be y = -2x - 5.

-Dan