The line `2x-y+1=0` is tangent to the circle at the point (2, 5) and the center of the circle lies on `x-2y=4` . Then find the radius of the circle.

The line 2x-y+1=0 is tangent to the circle at the point (2, 5) and the center of the circle lies on x-2y=4. The radius of the circle is

If the lines 3x-4y+4=0 and 6x-8y-7=0 are tangents to a circle, then find the radius of the circle.

If one end of the diameter is (1, 1) and the other end lies on the line x+y=3 , then find the locus of the center of the circle.

If the line lx+my+n=0 is tangent to the circle x^(2)+y^(2)=a^(2) , then find the condition.

A tangent at a point on the circle x^2+y^2=a^2 intersects a concentric circle C at two points Pa n dQ . The tangents to the circle X at Pa n dQ meet at a point on the circle x^2+y^2=b^2dot Then the equation of the circle is

2x+y=0 is the equation of a diameter of the circle which touches the lines 4x-3y+10=0 and 4x-3y-30=0. The centre and radius of the circle are

If y=4x+c is a tangent to the circle x^(2)+y^(2)=9 , find c.

If a circle S(x, y)=0 touches at the point (2,3) of the line x+y=5 and S(1,2)=0 , then (sqrt2 xx Radius) of such circle is

Find the equations of the circles passing through the point (-4,3) and touching the lines x+y=2 and x-y=2