Equation of a Line

The inclination of a line

The inclination of a line is the angle it makes with the positive direction of the X-axis, measured anticlockwise. It always lies between 0° and 180°.

Slope is denoted by m

Slope is denoted by m and is defined as m = tan θ, where θ is the angle of inclination. A line parallel to the X-axis has slope 0, while a line parall

If a line passes through P(x1

If a line passes through P(x1,y1) and Q(x2,y2), then m = (y2-y1)/(x2-x1). This comes from the rise over run idea using the coordinate differences of t

If a line cuts the X

If a line cuts the X-axis at P and the Y-axis at Q, then OP is the X-intercept and OQ is the Y-intercept. The X-intercept is positive if P lies to the

Since the ordinate of every point

Since the ordinate of every point on the X-axis is zero, its equation is y = 0. Since the abscissa of every point on the Y-axis is zero, its equation