Q. A circle in the xy-plane has its center at (h,k) and radius r. What is an equation of the circle?
Identify center and radius: Identify the center and radius of the circle. The center is at (0,0) and the radius is 2.
Use standard form equation: Use the standard form equation for a circle, (x−h)2+(y−k)2=r2, where h and k are the coordinates of the center and r is the radius.
Substitute values into equation: Substitute the values into the equation: h=0, k=0, r=2. So, (x−0)2+(y−0)2=22.
Simplify the equation: Simplify the equation: x2+y2=4.
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