Question

Consider a circle whose equation is x2 + y2 – 2x – 8 = 0. Which statements are true? Select three options. The radius of the circle is 3 units.

The center of the circle lies on the x-axis.
The center of the circle lies on the y-axis.
The standard form of the equation is (x – 1)² + y² = 3.
The radius of this circle is the same as the radius of the circle whose equation is x² + y² = 9.

Answer 1

Equation of circle is (x-h)²+(y-k)²=r²

• x²+y²-2x-8=0
• x²-2x-8+y²=0
• x²-2x+1-9+y²=0
• (x-1)²+y²-9=0
• (x-1)²+(y-0)²=9
• (x-1)²+(y-0)²=3²

Radius=3

Centre (1,0)

• Centre lies on x axis

Option A and D are correct