3721.11 – Symmetric Lines

The lines $L$ and $K$ are symmetric to each other with respect to the line $y = x$ . If the equation of $L$ is $y = ax + b$ with $a \neq 0$ and $b \neq 0$ , then the equation of $K$ is

a. $\frac{1}{a}x + b$

b. $-\frac{1}{a}x + b$

c. $-\frac{1}{a}x-\frac{b}{a}$

d. $\frac{1}{a}x+\frac{b}{a}$

e. $\frac{1}{a}x-\frac{b}{a}$

Solution

e. $\frac{1}{a}x-\frac{b}{a}$

You can pick a couple of values for $a$ and $b$ and graph the lines to verify that your answer is correct.