If , 0 < < , is the angle between the positive x-axis and a nonhorizontal, nonvertical line L, show that the slope m

If θ, 0 < θ < π, is the angle between the positive x-axis and a nonhorizontal, nonvertical line L, show that the slope m of L equals tan θ. The angle θ is called the inclination of L.

(cos 0, sin e) - M