Question

If (-2,5) is the centre of the circle which
touches y-axis, then the equation of the circle is
1) x2 + y2 - 4x - 10y + 25 = 0
2) x2 + y2 - 4x - 10y + 4 = 0
3) x2 + y2 + 4x + 10y + 2 = 0
4 x2 + y2 + 4x - 10y + 25 = 0​

Answer 1

✥ Correct Option is 4

★ Required Solution:

If the circle touches Y- axis , then its x- coordinate has magnitude equal to radius (r).

∴ centre of circle is (−2,5).

Then, r=2

∴ Equation of circle is

(x+2)² + (y−5)² = 4

⇒x² + y² + 4x − 10y + 25 = 0