Mathematics for IGCSE & O level - Coordinate Geometry (Section 2 - No. 40)
What information do you need to determine the equation of a straight line?
The gradient and a point on the line.
Two points on the line.
The y-intercept and the x-intercept.
The length of the line segment.
Explicación
The gradient and a point (or two points) allow you to find the equation. The y- and x-intercepts also define a line. The length is irrelevant to deriving the equation.