If four points in the plane be taken and the square of the length of the tangents…

MATHEMATICS · Subjective · ICSE · Mathematics · Geometry · Geometry

Problem

If four points

P, Q, R, S

in the plane be taken and the square of the length of the tangents from

P

to the circle on

QR

as diameter be denoted by

\{P, QR\}

, show that

\{P, RS\} - \{P, QS\} + \{Q, PR\} - \{Q, RS\} = 0