App Detail » Circles and Equations

What's New

New practice option and enhanced user interface.

App Description

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.

App Changes

• June 25, 2011 New version 2.2
• August 12, 2012 New version 3.0
• September 27, 2012 New version 3.1
• February 16, 2013 New version 3.2
• September 27, 2013 New version 4.0
• April 13, 2015 New version 5.0
• September 26, 2015 New version 5.1
• November 09, 2016 New version 6.0
• June 14, 2019 New version 6.3
• September 26, 2019 New version 6.4
• September 27, 2019 New version 6.5
• January 14, 2020 Price decrease: $0.99 -> FREE!
• January 22, 2020 New version 6.6
• January 28, 2020 New version 6.7
• January 28, 2020 Price increase: FREE! -> $0.99
• August 06, 2021 New version 6.8