Equation of a Line Through Intersection and Perpendicular to Another Line

Equation of a Line Through Intersection and Perpendicular to Another Line

## Formula

If:

$$L_1+\lambda L_2=0$$

represents the family of lines through the intersection of $$L_1=0$$ and $$L_2=0$$, impose the perpendicularity condition:

$$A_1A_2+B_1B_2=0$$

for the required pair of lines.

## Usage

- Used to select a line from a family that is perpendicular to a specified line.