Circles and Equations app for iPhone and iPad

A power learning aid combines Coaching Calculator, Practice and Guide to help students master finding the center and radius of a circle by completing the square.

Develop skills with the Coaching Calculator as you find the center and radius of a circle step by step,

- Taking constant term to right hand side
- Grouping x-related and y-related terms
- Completing the squares
- Writing in center-radius form

or go straight to a particular step.

Check your progress with Practice as it presents you with circle equations from simple to more difficult.

Reference the Guide as it features step-by-step examples of circle equations where the coefficient of x² is one and not equal to one.

Applications include finding the equation of a tangent line at a a given point on a circle and determining if a given point is inside a circle.