A line drawn through the point P(4,7) cuts the circle x^2+y^2=9 at the points A and B.

Question

A line drawn through the point $P(4,7)$ cuts the circle $x^2+y^2=9$ at the points $A$ and $B$. Then $PA\cdot PB$ is equal to

Accepted Answer

Power of the point $P$ w.r.t. the circle: $OP^2-r^2=(16+49)-9=56$.

$$PA\cdot PB=56.$$

Solutions · 1