Method 2: two points (x 1, y 1) and (x2, y2) are known, and the slope k=(y2-y 1)/(x2-x 1). Indicates the inclination of a straight line (or tangent of a curve) with respect to a (horizontal) coordinate axis. It is usually expressed by the tangent of the angle between a straight line (or the tangent of a curve) and a (horizontal) coordinate axis, or the ratio of the difference between the ordinate and abscissa of two points.
The slope of extended data, also known as "angle coefficient", represents the amount of inclination of a straight line relative to the horizontal coordinate axis in a plane rectangular coordinate system.
The tangent value tgα of the inclination angle α of a straight line with respect to the X axis is called the "slope" of the straight line, which is denoted as k, and k=tgα. It is stipulated that the slope of the straight line parallel to the X axis is zero, and the slope of the straight line parallel to the Y axis does not exist. For a straight line passing through two known points (x 1, y 1) and (x2, y2), if x 1≠x2, the slope of the straight line is k = (y1-y2)/(x/kloc-0).
Reference Slope _ Baidu Encyclopedia