Question
Question: The circle x<sup>2</sup> + y<sup>2</sup> = 1 is completely contained in the circle x<sup>2</sup> + ...
The circle x2 + y2 = 1 is completely contained in the circle
x2 + y2 + 4x + 3y + k = 0, if
A
k< – 5
B
k < – 6
C
k < – 4
D
k < 0
Answer
k < – 6
Explanation
Solution
C1 (0,0) ; r1 = 1
C2(–2, –3/2) ; r2 =
̃ r2 = 425−k
one circle contained in the other then.
C1C2 < r2 – r1
25 < –1
̃ 27
̃ 4−24 ̃ k < – 6