The chord of contact of tangents from a point to a circle passes through

MATHEMATICS · Single correct · ICSE · Mathematics · Geometry · Geometry

Problem

The chord of contact of tangents from a point

P

to a circle passes through

Q

. If

l_1

and

l_2

are the lengths of tangents from

P

and

Q

to the circle, then

PQ

is equal to (1)

\frac{l_1 + l_2}{2}

(2)

\frac{l_1 - l_2}{2}

(3)

\sqrt{l_1^2 + l_2^2}

(4)

\sqrt{l_1^2 - l_2^2}