AP EAMCET2015MathematicsCircle
If x-y+1=0 meets the circle x^2+y^2+y-1=0 at A and B , then the equation of the circle with A B as diameter is
Options
- A2 (x^2+y^2 )+3 x-y+1=0
- B2 (x^2+y^2 )+3 x-y+2=0
- C2 (x^2+y^2 )+3 x-y+3=0
- Dx^2+y^2+3 x-y+4=0
Correct answer
A. 2 (x^2+y^2 )+3 x-y+1=0
Step-by-step solution
Given that circle, S=x^2+y^2+y-1=0 Line, L : x-y+1=0 Equation of the circle passing through the intersection of line and circle is given by aligned & S + L =0 & (x^2+y^2+y-1 )+ (x-y+1)=0 & x^2+y^2+ x+(1- ) y+ -1=0 aligned Centre of above circle = ( - 2 , -1 2 ) Since, centre lies on x-y+1=0 - 2 - ( -1 2 )+1=0 = 3 2 Now, the required equation of circle aligned & x^2+y^2+y-1+ 3 2 (x-y+1)=0 & 2 (x^2+y^2 )+3 x-y+1=0 aligned