Question
Question: The auxilary circle of the ellipse 9x<sup>2</sup> + 25y<sup>2</sup>-18x-100y-116=0...
The auxilary circle of the ellipse 9x2 + 25y2-18x-100y-116=0
A
(x+1)2 + (y+2)2 = 9
B
(x+1)2+(y+1)2=25
C
(x-1)2+(y-2)2 = 9
D
(x-1)2+(y-2)2 = 25
Answer
(x-1)2+(y-2)2 = 25
Explanation
Solution
The given ellipse can put in the form of
25(x−1)2+9(y−2)2=1, Here (α, β) = (1, 2) is the centre.
The equation of auxilary circle is (x - α)2 + (y-β)2 = a2
(x-1)2 + (y-2)2 = 25