Question
Question: x<sup>2</sup> + y<sup>2</sup> –4x – 6y + l = 0 touches x- axis then the value of l is...
x2 + y2 –4x – 6y + l = 0 touches x- axis then the value of l is
A
–4
B
4
C
–8
D
8
Answer
4
Explanation
Solution
Put y = 0; x2 – 4x + l = 0 give equal roots so D = 0
Ž 16 – 4l = 0 Ž l = 4