If the line y = 2x+3 is reflected in the line y = x+1, find what its equation becomes.
When you reflect a line over , you simply switch the x and y variables.
So becomes
The resulting equation of a line is also known as the inverse of the original equation.
In the problem, the line was reflected over , so you add to the inverse of the original equation.
If you drew and on graph paper and folded the paper at , the two lines should be right on top of each other.