The slope of a line can be intuitively defined as how steep the line is, relative to some coordinate system. To be more precise, given a line in the Cartesian plane and two points, and , on with , the slope of is equal to If all points on have the same -coordinate (abscissa), we say that has infinite slope.
Other expressions for the slope are
|(read "delta over delta "),
If is the directed angle between the -axis and , the slope is also given by .