The equation of the circle which intersects circles x2+y2+x+2y+3=0,x2+y2+2x+4y+5=0 and
x2+y2−7x−8y−9=0 at right angle, will be
Let circle be x2+y2+2gx+2fy+c=0. Then according to the conditions given,
g + 2f = c + 3 .........(i)
2g + 4f = c + 5 .........(ii)
-7g - 8f = c - 9 ..........(iii)
⇒g=23,f=23,c=−1
Therefore, the required equation is
3(x2+y2)+4(x+y)−3=0.