P and Q are 2 external points from which tangents are drawn to circle centered at origin and radius 'r' P≡(x1,y1),Q≡(x2,y2). What is the condition for the lengths of tangents to be the same?
What is the length of tangent from a point P(x1,y1) to the circle x2+y2+2gx+2fy+c=0.
For the line segment joining the points A(x1, y1, z1) and B(x2, y2, z2)
are
The equation of the circle which touches both axis and whose centre is x1,y1 is