Question
Question: The circle whose diameter is the chord x + y = 1 of the circle x<sup>2</sup> + y<sup>2</sup> = 4 is...
The circle whose diameter is the chord x + y = 1 of the circle x2 + y2 = 4 is
A
x2 + y2 – x – y – 3 = 0
B
x2 + y2 – 2x – 2y – 6 = 0
C
x2 + y2 + x + y + 3 = 0
D
None of these
Answer
x2 + y2 – x – y – 3 = 0
Explanation
Solution
S + lP = 0. Its centre lies on P = 0
\ l = –1
so x2 + y2 – x – y – 3 = 0