The Circle

• 1. Equation of Externally touching Circles. Point of contact, Equation of tangent at point of contact.
• 2. Centre and radius given equation of circle. Prove circles are touching, Verify point on both circles, Equation of common tangent.
• 3. Equation of new circle form intersection of line and other circle.

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For Registered Users

4. Calculate radius and centre from equation of circle.

5. Given Equation of circle & radius – find value of a constant. Equation of circles with X & Y axis as tangents.

6. Equation of circle lying on a line with X & Y axis as tangents.

7. Centre/Radius from equation of circle. Centre – given perpendicular distance form line to centre. Equation of circle given three points on circle.