Question

Find slope of line make angle of 30°with positive direction of y- axis measured anticlockwise.

Answer 1

x = 120

slope = m = tan(x)

                = tan(120) = tan(180 - 60)

Since tan(180 - a) = -tan(a)

therefore,

               tan(180 - 60) = -tan(60) = $\sqrt{3}$

slope of line = - $\sqrt{3}$