Find the equation of a circle which touches both the axes and the line 3x−4y+8=0 and lies in the third quadrant.
The circle is as shown in figure.
x1=∣∣3x1−4y1+85∣∣=y1
5x1=−3x1+4y1−88x1=−4x1=−8 …(1)−5y1=−3x1+4y1+83x1+4y1=8 …(2)Solving(1)and(2)weget,x1=2,y1=2
As centre is in third quadrant, centre (x1,y1)=(−2,−2)
Equation of the circle with centre (-2,-2) and radius 2 is (x+2)2+(y+2)2=4
x2+4x+4+y2+4y+4=4x2+y2+4x+4y+4=0