Question

The equation of the circle drawn with the focus of the parabola (x - 1)2–8y=0 as its centre and touching the parabola at its vertex is (A) x2 + y2 – 4y = 0 (B) x2 + y2 – 4y + 1 = 0 (C) x2 + y2 – 2x – 4y = 0 (D) x2 + y2 – 2x - 4y + 1 = 0 ​

Answer 1

Answer:

d

Step-by-step explanation:

(x – 1)2 = 8y ; a = 2 x – 1 = 0, y = 2 x2 = 8y ; x = 1, y = 2 vertex (1, 0) Focus (1, 2)  Radius of circle = 2 (x – 1)2 + (y – 2)2 = 4 x2 + y2 – 2x – 4y + 1 = 0