Q5 of 85 Page 233

Find perpendicular distance from the origin to the line joining the points and

The equation of the line joining the points (cosƟ, sinƟ) and (cosɸ, sinɸ) is given by



y(cosɸ-cosƟ) sinƟ(cosɸ-cosƟ) = x(sinɸ-sinƟ) cosƟ(sinɸ-sinƟ)


x(sinƟ- sinɸ) + y(cosɸ- cosƟ) + cosƟsinɸ - cosƟsinƟ sinƟcosɸ + sinƟcosƟ = 0


x(sinƟ- sinɸ) + y(cosɸ- cosƟ) + sin(ɸ-Ɵ) = 0


Ax + By + C = 0, where A = sinƟ- sinɸ, B = cosɸ- cosƟ, and C = sin(ɸ-Ɵ)


It is known that the perpendicular distance (d) of the line Ax + By + C = 0 from a point


(x1, y1) is given by



Thus, the perpendicular distance (d) of the given line from point (x1, y1) =(0,0) is









More from this chapter

All 85 →