Question

Classify the following equation:
x2 + 4y2 - 2x + 16y + 13 = 0
Answer

Parabola
Circle
Line
None of the above

Answer 1

x^2 + 4y^2 - 2x + 16y + 13 = 0
x^2 + 4y^2 - 2x + 16y = -13
(x - 1)^2 + 4(y + 2)^2 = 4
(x - 1)^2/4 + (y + 2)^2/1 = 1

It is none of the above because this is the form for an ellipse and not a circle of a line.