Name

**Slopes of line segments.**
Graph	Formulas
	[math]\text{Horizontal line}\,[/math] [math]\alpha =0\,[/math] [math] \tan \alpha=0\,[/math] [math] m=0\,[/math]
	[math]\text{Vertical line}\,[/math] [math]\alpha =90^\circ\,[/math] [math] \tan \alpha=\infty[/math] [math] m=\text{Undefined}\,[/math] [math]\text{A vertical line has no slope}\,[/math]
	[math]\text{Upward line from left to right}\,[/math] [math]0 \lt \alpha \lt90^\circ\,[/math] [math] 0\lt\tan \alpha\lt\infty[/math] [math] m\gt0\qquad\text{Positive slope}\,[/math]
	[math]\text{Downward line from left to right}\,[/math] [math]90^\circ\lt\alpha\lt180^\circ\,[/math] [math] -\infty\lt\tan \alpha\lt0[/math] [math] m\lt0\qquad\text{Negative slope}\,[/math]

Usage