Question

The chord of contact of pair of tangents drawn from a point $P$ to the circle $x^2+y^2=1$ passes through a fixed point $(1/2,1/4)$. Then $P$lies

• A. On the line $x+2y=4$
• B. On the line $2x+y=4$
• C. On the line $x-y=4$
• D. None of the these

Answer 1

Answer: (B)

On the line $2x+y=4$

Equation of chord contact

$hx+ky=1$

Since, point $(1/2,1/4)$

Therefore,

$\frac{1}{2}x+\frac{1}{4}y=12x+y=4$

Hence, this is the answer.