Equation of Circles (Repeat)

What is the equation of a circle with centre (7, 0) with radius 3?

• (x - 7)² + y² = 9

• x² + (y - 7)² = 9

• (x - 7)² + y² = 3

• x² + (y - 7)² = 3

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

• Centre (4,3), Radius = 25 units

• Centre (-4,-3), Radius = 25 units

• Centre (4,3), Radius = 5 units

• Centre (-4,-3), Radius = 5 units

Which circle is identical to x² + y² - 4x + 12y - 8=0?

• (x + 2)² + (y - 6)² = 48

• (x - 2)² + (y + 6)² = 48

• (x - 6)² + (y - 2)² = 48

• (x + 2)² + (y - 6)² = 48

The end-points of the diameter of a circle are (3,1) and (9,5).

What is the equation of the circle?

• (x − 3)² + (y − 2)² = 1

• (x − 3)² + (y − 2)² = 45

• (x − 5)² + (y − 9)² = 13

• (x − 6)² + (y − 3)² = 13

The centre of a circle is (−8, 3) and (2, −5) lies on the circle.

Find the equation of the circle.

• (x + 8)² + (y − 3)² = 144

• (x − 8)² + (y + 3)² = 144

• (x + 8)² + (y − 3)² = 164.

• (x − 8)² + (y + 3)² = 164

Find an equation of the circle that is tangent to both the x and y axes, with a radius of 4 and whose centre is located in the second quadrant.

• (x + 4)² + (y - 4)² = 16

• (x - 4)² + (y + 4)² = 16

• (x + 4)² + (y - 4)² = 4

• (x - 4)² + (y + 4)² = 4

The equation of a circle is given by x ² + 4x + y ² - 8y = 5.

Is the point A(-3 , 8) inside, outside or on the circle?

• inside

• outside

• on the circumference

Find the equation of the circle whose diameter has end-points at (-5, 2) and (3, 6).

• (x + 4)² + (y + 2)² = 20

• (x - 4)² + (y + 2)² = 20

• (x + 1)² + (y - 4)² = 20

• (x - 1)² + (y + 4)² = 20

What is the radius of the circle x² + y² - 10x + 8y - 23 = 0?

• 8

• 32

• 64

• none of these answers

Which equations represents a circle?

• x² + y² + 36 = 0

• x² + 4x + y² - 6y - 12 = 0

• 3x² + 6x + 3y² - 30y + 3 = 0

• 2x² + 8x + 4y² - 10y = 12