9. Equations of Circles

9.01 Extending Completing the Square

9.02 Introducing the Equation of a Circle

9.03 Generalising the Equation of a Circle using a Translation

9.04 Circles: Finding the Equation, Centre and/or Radius

9.05 Finding the Centre and Radius of x^2 + y^2 + 2x - 6y - 14 = 0

9.06 Finding the Equation of a Circle given its Centre and a Point on the Circle

9.07 Finding where the circle (x - 2)^2 + (y - 3)^2 = 100 crosses the Coordinate Axes

9.08 Determining whether points lie Inside, On, or Outside of the Circle

9.09 A Coordinate Geometry Exam-Style Problem Involving a Circle

9.10 Introducing Circle Theorem 1: Right-Angled Triangles

9.11 Using Circle Theorem 1

9.12 Introducing Circle Theorem 2: Tangents and Normals

9.13 Using Circle Theorem 2

9.14 The Intersection of a Line and a Curve: Three Situations

9.15 Determining whether a Line Intersects a Circle

9.16 Finding the values of k for which y = -2x + k is a Tangent to a Circle

9.17 EXTENSION: Finding the values of k for which y = 3x + k is a Tangent to a Circle

9.18 Finding the Intersection of a curve and a Straight Line by Plotting