Question

Consider a circle whose equation is x2 + y2 – 2x – 8 = 0. Which statements are true? Check all that apply.
A.The radius of the circle is 3 units.
B.The center of the circle lies on the x-axis.
C.The center of the circle lies on the y-axis.
D.The standard form of the equation is (x – 1)² + y² = 3.
E.The radius of this circle is the same as the radius of the circle whose equation is x² + y² = 9.

Answer 1

Answer:

x^2 + y^2 - 2 x - 8 = 0 = (x -4) (x + 2) + y^2

A.   When y = 0 the crosses the x-axis at x = 4 and x = -2

The diameter is then 6 units and the radius is 3 units.

B.  True   from part A

C.  False   the center of the circle lies at x = 1

D.   False    (x - 1)^2 + y^2 = 9    for a circle of radius 3 centered at x=1

E.    True    when x = 0   y = 3

                  when y = 0 x = 3

Answer 2

Answer:

B and C

Step-by-step explanation:

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