Equation of a Line
Algebraic equation of the form Ax + By + C = 0, where A, B and C are real numbers and where A and B are not both zero.
In the general form of the equation of the line Ax + By + C = 0, the parameters A, B and C are usually non-zero real numbers, since:
- if A = 0, then the line is horizontal (parallel to the x-axis);
- if B = 0, then the line is vertical (parallel to the y-axis);
- if C = 0, then the line passes through the origin (0, 0).
Example
The equation 4x − 2y + 1 = 0 is the equation of a line whose slope is m = 2 and whose y-intercept is [latex]\frac{1}{2}[/latex].