Circles Page 9

Page 9

Summary of Steps for Rewriting the Equation
of a Circle from General to Standard Form

STEP 1: Collect like terms together on one side of the equation.

STEP 2: Move constant terms to the other side of the equation.

STEP 3: Factor the coefficient of x² and y² out of the entire equation.

STEP 4: Complete the squares, adding necessary numbers to both sides of the equation.

STEP 5: Simplify.

(x - h)² + (y - k)² = r²

blue circle:	x² + y² - 6x - 8y + 21 = 0
green circle:	16x² + 16y² + 232x - 8y + 761 = 0

STEP 1:	Collect like terms together on one side of the equation.
STEP 2:	Move constant terms to the other side of the equation.
STEP 3:	Factor the coefficient of x² and y² out of the entire equation.
STEP 4:	Complete the squares, adding necessary numbers to both sides of the equation.
STEP 5:	Simplify.