Question
Question: The equation of the circle which touches both the axes and the straight line 4x + 3y = 6 in the firs...
The equation of the circle which touches both the axes and the straight line 4x + 3y = 6 in the first quadrant and lies below it is :
A
4x2 + 4y2– 4x – 4y + 1 = 0
B
4x2 + y2– 6x – 6y + 9 = 0
C
x2 + y2– 6x – y + 9 = 0
D
4(x2 + y2– x – 6y) + 1 = 0
Answer
4x2 + 4y2– 4x – 4y + 1 = 0
Explanation
Solution
Let radius of circle is r
Ž C ŗ (r, r) Q Pt. touches 4x + 3y – 6 = 0
P = r Ž 5∣4r+3r−6∣=r Ž 7r – 6 = ± 5r
12r = 6, 2r = 6 Ž r = 1/2, r = 3
Q r = 3 not possible
Ž r = 1/2 Equation (x –1/2)2 + (y –1/2)2 = ¼