## Precalculus (6th Edition) Blitzer

Center: $(0, 0)$ Radius = 4 Domain: $[-4, 4]$ RangeL $[-4, 4]$ Refer to the image below for the graph.
RECALL: The standard equation of a circle whose center is at $(h, k)$ and has a radius of $r$ units is: $(x-h)^2 + (y-k)^2 = r^2$ Thus, using the standard form given above as guide, the given circle has: Center: $(0, 0)$ Radius = $\sqrt{16} = 4$ To graph the circle, perform the following steps: (1) Plot the center $(0, 0)$. (2) From the center, plot the points 4 units to the center’s left, right, above, and below. These points are $(-4, 0)$, $(4, 0)$, $(0, 4)$, and $(0, -4)$, respectively. Connect these points using a curve to form a circle. The domain is the set of x-values covered by the graph. Since the graph covers the x-values from -4 to 4, then the domain is: $[-4, 4]$ The range is the set of y-values covered by the graph. Since the graph covers the y-values from -4 to 4, then the range is: $[-4, 4]$