Question

Find the slopes of lines PQ and PR. (Assume a ≠ -b.) P(a, a + b); Q(a + b, b); R(a - b, a)slope of PQ = ?slope of PR = ?

Answer 1

We know that the slope of a line is:

$m=\frac{y_2-y_1}{x_2-x_1}$

So for the line PQ will be:

$m=\frac{b-(a+b)}{a+b+a}=\frac{-a}{2a+b}$

and for the line PR will be:

$m=\frac{a-(a+b)}{a-b-a}=\frac{-b}{-b}=1$