Find the radius of the circle x^2+y^2-6x+2y+6 = 0.
Answer and explanation
Correct answer: A. 2
- Step 1: Complete the square: (x - 3)^2 + (y + 1)^2 = 4.
- Step 2: The radius is the square root of 4, which is 2.
Answer
2.
Why not the others: '4' reports r^2 instead of r; '6' uses the constant term as the radius; '3' adds one in completing the square.
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