Question

Find the centre and radius of the circle 3x²+3y²-6x+4y-1​

Answer 1

Step-by-step explanation:

Given equation is 3x2 + 3y2 + 6x – 4y – 1 = 0

Or x2 + y2 + 2x – 4/3 y – 1/3 = 0

The general equation of a circle is as follows:

x2 + y2 + 2gx + 2fy + c = 0

Where g, f and c are constants.

With

Centre: (-g, -f)

On comparing given equation with general form of circle, we have

2g = 2 ⇒ g = 1

2f = -4/3 ⇒ f = -2/3 and

c = -1/3

Now,

Centre (-g, -f) = (-1, 2/3)