A circle `C` and the circle `x^2 + y^2 =1` are orthogonal and have radical axis parallel to y-axis, then `C` can be : (A) `x^2 + y^2 + 1 = 0` (B) `x^2 + y^2 + 1 = y` (C) `x^2 + y^2 + 1 = -x` (D) `x^2 + y^2 - 1 = -x`

Tangents OA and OB are drawn from the origin to the circle (x-1)^2 + (y-1)^2 = 1 . Then the equation of the circumcircle of the triangle OAB is : (A) x^2 + y^2 + 2x + 2y = 0 (B) x^2 + y^2 + x + y = 0 (C) x^2 + y^2 - x - y = 0 (D) x^2+ y^2 - 2x - 2y = 0

At what points on the circle x^2+y^2-2x-4y+1=0 , the tangent is parallel to the x-axis.

At what point on the circle x^(2)+y^(2)-2x-4y+1=0, the tangent is parallel to x-axis.

The locus of the mid-point of a chord of the circle x^2 + y^2 -2x - 2y - 23=0 , of length 8 units is : (A) x^2 + y^2 - x - y + 1 =0 (B) x^2 + y^2 - 2x - 2y - 7 = 0 (C) x^2 + y^2 - 2x - 2y + 1 = 0 (D) x^2 + y^2 + 2x + 2y + 5 = 0

If x^2/a +y^2/b=1 and x^2/c+y^2/d=1 are orthogonal then relation between a , b , c , d is

At what point on the circle x^(2)+y^(2)-2x-4y+1=0 the tangent is parallel to (1) X-axis (2) Y-axis

Equation of radical axis of the circles x^(2) + y^(2) - 3x - 4y + 5 = 0 and 2x^(2) + 2y^(2) - 10x - 12y + 12 = 0 is

The centres of the circles x ^(2) + y ^(2) =1, x ^(2) + y^(2)+ 6x - 2y =1 and x ^(2) + y^(2) -12 x + 4y =1 are

The equation of a tangent parallel to y=x drawn to (x^2)/3 - (y^2)/2=1 is a.x-y+1=0 b. x-y+2=0 c. x+y+1=0 d. x-y-2=0

The intercept on the line y=x by the circle x^2+y^2-2x=0 is AB. Equation of the circle with AB as a diameter is (A) (x-1/2)^3+(y-1/2)^2=1/2 (B) (x-1/2)^2+(y-1/2)^2=1/4 (C) (x+1/2)^2+(y+1/2)^2=1/2 (D) (x+1/2)^2+(y+1/2)^2=1/4