Equations of Circles Using Completing the Square

• A
• B
• C
• D

What do you do to the b value to correctly complete the square?

• square it

• divide it by 2 and square the result

• divide it by 2 and take the square root of the result

• divide it by 2 only

Complete the square for

x² - 12x + ____

• 144

• 36

• - 36

• 24

What is the coordinates of the centre and the radius of the circle with equation:
(x - 4)^2 + (y - 3)^2 = 25^ ?

• Centre  (4,3)
  Radius = 5 units

• Centre  (4,3)
  Radius = 25 units

• Centre  (-4,-3)
  Radius = 25 units

• Centre  (-4,-3)
  Radius = 5 units

A circle has the equation  x² + y² - 12x + 8y + 3 = 0.  Use completing the square to write the equation in standard form.

• (x - 6)² + (y + 4)² = 49

• (x + 4)² + (y - 6)² = 49

• (x - 6)² + (y + 4)² = 55

• x² + y² = 55

Which of the following graphs match the equation:

• 
• 
• 
• 

In the equation (x+2)²+(y-3)²=4, the radius of the circle is...

• 4

• 2

• 3

• 16

Write the equation of the circle in standard form:

• A

• B

• C

• D

Write the equation of the circle in standard form:

• A

• B

• C

• D

Which equation matches the graph?