A. h2+k2+4h+4k+16=0
B. h2+k2+3h+3k=0
C. 3h2+3k2+8h+8k+16=0
D. 3h2+3k2+4h+4k+16=0
The equation of the circle concentric with circlex2+y2-6x+12y+15=0 and of double its area is
The equation of the circle passing through the points of intersection of the circlesx2+y2=5, x2+y2+12x+8y-33=0 and touching x-axis is
If 4y=x+7 is diameter of the circumscribing circle of the rectangle ABCD and A(-3, 4), B(5, 4), then the area of the rectangle is
The polar of the point(2t, t-4) w.r.t the circle x2+y2-4x-6y+1=0 passes through the point
The locus of midpoints of chords of the circle x2+y2=2r2 subtending a right angle at the centre of the circle is
The centres of the circles are (a, c) and (b, c) and their radical axis is the y-axis. The radius of one of the circle is r. The radius of the other circle is
The tangents drawn from the origin to the circle x2+y2-2rx-2hy+h2=0 are perpendicular if
If x2+y2-2x+3y+k=0 and x2+y2+8x-6y-7=0 cut each orthogonally, the value of k must be
The equation of the circle passing through the intersection of the circles x2+y2=2ax and x2+y2=2by and having its centre on the x/a-y/b=2 is
If O is the origin and OP, OQ are the tangents to the circles x2+y2+2gx+2fy+c=0 then the circumcentre of the ΔOPQ is