Consider the circle `x^(2)+y^(2)-4x-2y+c=0` whose centre is A(2, 1) If the point P (10, 7) is such that the line segment PA meets the circle in Q With PQ=5, then c=

Lines are drawn through the point P(-2,-3) to meet the circle x^(2)+y^(2)-2x-10y+1=0 The length of the line segment PA,A being the point on the circle where the line meets the circle at coincident points,is 4sqrt(k) then k is

Let A be the centre of the circle x^(2)+y^(2)-2x-4y-20=0 . If the tangents at the points B (1, 7) and D(4, -2) on the circle meet at the point C, then the perimeter of the quadrilateral ABCD is

Let A be the centre of the circle x^(2)+y^(2)-2x-4y-20=0 . If the tangents at the points B (1, 7) and D(4, -2) on the circle meet at the point C, then the perimeter of the quadrilateral ABCD is

A tangent to the circle x^2 + y^2 = 1 through the point (0, 5) cuts the centre x^2 + y^2 = 4 at P and Q. The tangents to the circle x^2 + y^2 = 4 at P and Q meet at R. Then the co-ordinates of R are :

A tangent to the circle x^(2)+y^(2)=1 through the point (0, 5) cuts the circle x^(2)+y^(2)=4 at P and Q. If the tangents to the circle x^(2)+y^(2)=4 at P and Q meet at R, then the coordinates of R are

A tangent to the circle x^(2)+y^(2)=1 through the point (0, 5) cuts the circle x^(2)+y^(2)=4 at P and Q. If the tangents to the circle x^(2)+y^(2)=4 at P and Q meet at R, then the coordinates of R are

The equation of the tangent to the circle x^2+y^2=50 at the point, where the line x+7=0 meets the circle, is

A line y=2x+c intersects the circle x^(2)+y^(2)-2x-4y+1=0 at P and Q. If the tangents at P and Q to the circle intersect at a right angle,then |c| is equal to