Find the radius of the circle 2x\(^2\) – 4x + 2y\(^2\) – 6y -2 = 0.
- 17/4
- 17/2
-
17/√2
- √17/2
The correct answer is: C
Explanation
2x\(^3\) - 4x + 2y\(^2\) - 6y - 2 = 0
Divide through by 2: x\(^2\) - 2x + y\(^2\) -3y -1 = 0
x\(^2\) -2x + y\(^2\) - 3y = 1
x\(^2\) -2x + 1 + y\(^2\) - 3y + 9/4
= 1+ 1 + 9/4
= (x- 1)\(^2\) (y - 3/2)\(^2\)
= √[17/4]
r = √17/2