Topic explanation

Standard explanation

x^2+y^2+Dx+Ey+F=0 represents a real circle when the computed radius squared is positive.

Key points

• General equation of a circle
• rule
• worked example
• General equation of a circle: x^2+y^2+Dx+Ey+F=0 represents a real circle when the computed radius squared is positive.
• CONCEPT AND RULE: x^2+y^2+Dx+Ey+F=0 represents a real circle when the computed radius squared is positive.
• METHOD: For general equation of a circle, identify the given information and required result. Select the mat
• x^2+y^2+Dx+Ey+F=0 represents a real circle when the computed radius squared is positive.
• Worked pattern: Centre is (-D/2,-E/2).

Labelled diagram