Explanation

(b)
Given parameter equation are
$\cos\theta = \frac{x - 2}{3}\ \ and\ \sin\theta = \frac{y + 1}{3}$
Since, $\cos^{2}\theta + \sin^{2}\theta = 1$
$\Rightarrow \ \ \ \left( \frac{x - 2}{3} \right)^{2} + \left( \frac{y + 1}{3} \right)^{2} = 1$
$\Rightarrow \ \ \ (x - 2)^{2} + (y + 1)^{2} = 3^{2}\$
$\therefore$ Centre of circle is $(2,\ - 1)$