Find the equation of the circle with:  centre (0,-1) and radius 1.

Explanation

To find the equation of a circle with a given center and radius, we can use the standard form of the equation of a circle. The standard equation of a circle with center (H, K) and radius A is given by:

\[ (x - H)^2 + (y - K)^2 = A^2 \]

### Step-by-step Solution:

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