Question

Find the parametric equations of the circle x2 + y2 – 4x – 2y + 1 = 0

Answer 1

We have : x2 + y2 – 4x – 2y + 1 = 0

⇒ (x2 – 4x ) + (y2 – 2y) = – 1

⇒ (x – 2)2 + (y – 1)2 = 22

So, the parametric equations of this circle are

x = 2 + 2 cos θ , y = 1 + 2 sin θ.