Slope of Normal
( ii) If, then normal at( x, y) is parallel to y-axis and perpendicular to x-axis.
( iii) If then normal at( x, y) is parallel to x-axis and perpendicular to y-axis.
Length of Tangent and Normal( i) Length of tangent, PA = y cosec θ =
( ii) Length of normal,
( iii) Length of subtangent,
( iv) Length of subnormal,