Question
Question: ax<sup>2</sup> + 2bxy + 2y<sup>2</sup> – 8x – 12y – 6 = 0 represents a circle if...
ax2 + 2bxy + 2y2 – 8x – 12y – 6 = 0 represents a circle if
A
a = 2, b = 0
B
a = 2, b = 1
C
a = b = 1
D
a = 2, b = 2
Answer
a = 2, b = 0
Explanation
Solution
General equation of 2nd degree
ax2 + 2hxy + by2 + 2gx + 2fy + c = 0
represents a circle if a = b & h = 0