represents a circle. Find its centre and radius.Answer:
The general equation of a conic is,
ax2 + 2hxy + by2 + 2gx + 2fy + c = 0
a, b, c, f, g, h are constants
For a circle, a = b and h = 0.
The equation is,
x2 + y2 + 2gx + 2fy + c = 0
x2 + y2 – 4x + 6y – 5 = 0
The equation represents a circle with 2g = – 4
g = – 2, 2f = 6
f = 3 and c = – 5
Centre ( – g, – f)
=> { – ( – 2), – 3}
=> (2, – 3).
