Find the equation of the circle with centre at (0, 0) and radius 4.

Explanation

To find the equation of the circle with center at (0, 0) and radius 4, we can follow these steps:

### Step 1: Identify the center and radius
The center of the circle is given as (0, 0), which means:
- \( a = 0 \)
- \( b = 0 \)

The radius \( R \) is given as 4.
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