Question

The greatest distance of the point $P(10,7)$ from the circle $x^2+y^2-4x-2y-20=0$ is-

• A. $5$
• B. $15$
• C. $10$
• D. None of these

Answer 1

The correct option is B $15$

Centre and radius of the given circle are $C(2,1)$ and $\sqrt{4+1+20}=5$ respectively.
Now $CP=\sqrt{8^2+6^2}=10$. Hence greatest distance of point P from the given circle is $=10+r=15$