Question

If the straight line x – 2y + 1= 0 intersects the circle x² + y²= 25 in the points P and Q, then the coordinates of the point of intersection of tangents drawn at P and Q to the circle, are –

• A. (25,50)
• B. (–25, –50)
• C. (–25, 50)
• D. (25, –50)

Answer 1

Answer: (C)

(–25, 50)

Answer 2

\ equation of chord of contact is, T = 0

hx + ky – 25 = 0

compare with x – 2y + 1 = 0  $\frac { \mathrm { h } } { 1 } = \frac { \mathrm { k } } { - 2 } = \frac { - 25 } { 1 }$

h = – 25, k = 50