Equation of a Line Through Intersection and Parallel to Another Line

Equation of a Line Through Intersection and Parallel to Another Line

## Formula

If the intersection of:

$$L_1=0,\quad L_2=0$$

is required to be joined by a line parallel to:

$$Ax+By+C=0$$

then use the corresponding slope condition with:

$$L_1+\lambda L_2=0$$

## Usage

- Used to determine a member of a family of lines satisfying an additional parallelism condition.