slope, also known as "angle coefficient", indicates the degree of inclination of a straight line relative to the abscissa axis. the tangent value of the angle between a straight line and the positive half-axis direction of the abscissa axis of a plane's cartesian coordinate system is the slope of the straight line relative to the coordinate system. if the straight line and the x-axis are perpendicular to each other, the tangent of the right angle is infinite, so the straight line has no slope. when the slope of the straight line l exists, for a linear function y=kx+b, (slope-intercept form) k is the slope of the image of the function.

when the slope of straight line l exists, the slope-intercept formula y=kx+b when k=0 y=b

when the slope of straight line l exists, the point slope formula y2—y1=k(x2—x1),

when the straight line l has a non-zero intercept on the two coordinate axes, there is an intercept formula x/a+y/b=1

for any point on any function, its slope is equal to the angle between its tangent and the positive direction of the x-axis, that is, tanα

slope calculation: ax+by+c=0, k=-a/b.

straight line slope formula: k=(y2-y1)/(x2-x1)

the product of the slopes of two perpendicular intersecting straight lines is -1: k1*k2=-1.