01. Equation of the circles having the center at and radius is
02. Equation of the circle having the center and radius is
03. Equation of the circle in general form is , whose centre is at and radius is
04. Equation of the circle passing through the point of intersection of the circles and is .
05. If and are the equations of two intersecting circles, then is the equation of the common chord.
06. If and are the equations of two circles such that they touch each other, then is the equation of the common tangent.
07. If and are the equations of two non-intersecting circles, then is the equation of radical axis.
08. The length of the tangent segment from a point to the circle is given by
09. A system of circles coaxal with the circles and is