Answer:
[tex] {x}^{2} + {y}^{2} + 4x - 2y = - 1 \\ ( {x}^{2}+2\times2\times x + {2}^{2} ) - 4 + ({y}^{2} - 2 \times 1 \times y + {1}^{2} ) - 1 = - 1 \\ {(x + 2)}^{2} - 4 + {(y - 1)}^{2} - 1 = - 1 \\ {(x + 2)}^{2} + {(y - 1)}^{2} = 4\\ {(x + 2)}^{2} + {(y - 1)}^{2} = {( 2) }^{2} [/tex]
Therefore, the centre of the circle is in ( -2, 1 )
and the radius of the circle is 2.
Formula used :-----
[tex] {(x - a)}^{2} + {(y - b)}^{2} = {r}^{2} [/tex]
equation of the circle
where r is the radius of the circle.
(A) 2 is the right answer.
