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Using the Slope Formula With Perpendicular Lines

Draw two perpendicular lines. Use the slope formula to demonstrate that their slops are negative reciprocals.

$m=\frac{\Delta y}{\Delta x}= \frac{y_{2}-y_{1}}{x_{2}-x{1}}$

line 1:

$m=\frac{3-1}{0-(-2)}= \frac{2}{2}=1$

line 2:

$m=\frac{-1-1}{0-(-2)}= \frac{-2}{2}=-1$

$m\Rightarrow\ -\frac{1}{m}$

$-\frac{1}{1}=-1$