Question 19
Coordinate GeometryFind the radius of the circle x2 + y2 − 8x − 2y + 1 = 0.
- A.9
- B.7
- C.4
- D.3
Show the answer and explanation
Answer: C (4)
Explanation
Centre (4, 1); r² = 16 + 1 − 1 = 16, so r = 4.
Find the radius of the circle x2 + y2 − 8x − 2y + 1 = 0.
Answer: C (4)
Centre (4, 1); r² = 16 + 1 − 1 = 16, so r = 4.