The foot of the perpendicular drawn from (0, 0) to the line xcosα+ysinα−p=0 is
∴xcosα+ysinα−p=0
From the formula for foot of perpendicular,
x2−0cosα=y2−0sinα=−(0×cosα+0×sinα−p)(cos2α+sin2α)=p
x2=+pcosα1=pcosα
y2=psinα