# Perpendicular Slope

• January 16th 2008, 08:24 AM
zachcumer
Perpendicular Slope
How do you find perpendicular slope is it: Y sub 1 minus Y sub 2 divided by X sub 1 minus X sub 2.?

Best
• January 16th 2008, 08:29 AM
colby2152
Quote:

Originally Posted by zachcumer
How do you find perpendicular slope is it: Y sub 1 minus Y sub 2 divided by X sub 1 minus X sub 2.?

Best

Say you have two coordinates $(x_1,y_1)$ and $(x_2,y_2)$.

The slope is simply: $\frac{y_2-y_1}{x_2-x_1}$

Perpendicular slope, and the tangent normal to this point is the opposite reciprocal of that slope: $\frac{x_1-x_2}{y_2-y_1}$