" (vii) "y^(2)-4y-21

Find the equation to the circle orthogonal to the two circles x^(2)+y^(2)-4x6y+11=0;x^(2)+y^(2)-10x-4y+21=0 and has 2x+3y=7 as diameter.

The least length of chord passing through (2,1) of the circle x^(2)+y^(2)-2x-4y-13=0 is

The least length of chord passing through (2,1) of the circle x^(2)+y^(2)-2x-4y-13=0 is

The least length of chord passing through (2,1) of the circle x^(2)+y^(2)-2x-4y-13=0 is

Factorise the y ^(2) + 4y - 21

Prove that the centres of the circles x^(2) + y^(2) - 10x + 9 = 0, x^(2) + y^(2) - 6x + 2y + 1 = 0 and x^(2) + y^(2) - 18x - 4y + 21 = 0 lie on a line, find the equation of the line on which they lie.

(3,-4) is the point to which the origin is shifted and the transformed equation is X^(2)+Y^(2)=4 then the original equation is (A) x^(2)+y^(2)+6x+8y+21=0 (B) x^(2)+y^(2)+6x+8y-21,=0 (C) x^(2)+y^(2)-6x+8y+21=0 (D) x^(2)+y^(2)-6x-8y+21=0

Find equation of circle concentric with circle 4x^(2)+4y^(2)-12x-16y-21=0 and of half its area.

Find the coordinates of the centre and the radius of the circles whose equations are 4x^(2)+4y^(2)-16x-12y+21=0