The slope m of a line making an angle θ with the positive direction of x axis in anticlockwise direction is given by,
m=tan θ 1 (1)
Let θ 1 be the angle subtended by the line with the positive direction ofx-axis in anticlockwise direction.
The angle made by the line with the positive direction ofx-axis in anticlockwise direction is,
θ 1 =90°+30° =120°
Substitute the value of θ 1 as 120° in equation (1).
m=tan120° =tan( 90°+30° ) =−cot( 30° ) =− 3
Thus, the slope of the line makes an angle of 30° with the positive direction ofy-axis in anticlockwise direction. is − 3 .
Find the slope of a line (i) which bisects the first quadrant angle (ii) which makes an angle of 30∘ with the positive direction of y-axis measured anticlockwise.