A) x + 3y + 1 = 0 is the chord of contact of point P (x1,y1) xx1 + yy1 (x + x1) + 2 (y + y1) + 1 = 0 x (x1 - 1) + y (y1 + 2) x1 + 2y1 + 1 = 0 comparing
⇒ b = 3 & a = b hence a = 3 (D) Circle with either at (8 . 6) and radius '4' is (x−8)2 + (y−6)2 = 16 ⇒ z2+y2 - 16x - 12y + 84 = 0 ..... (1) given circle x2+y2 - 100 = 0 ..... (2) Equation of QR is 4x + 3y - 46