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The radius r of a circle can be written as a function of the area A with the following equation: What is the domain of this function? Explain why it makes sense in this context.

Verified Answer :

[0,infinity) because you can not take the radius of a negative mumber.

Answer:

Hence, the domain of the function is:

[0,∞)

Step-by-step explanation:

We know that area of circle is given by the function:

\(A=\pi r^2\)

The radius r of a circle can be written as a function of the area A with the following equation:

Now we can represent r in terms of A as:

\(r^2=\dfrac{A}{\pi}\\\\r=\sqrt{\dfrac{A}{\pi}}\)

Now as we know that for the square root term to exist:

\(\sqrt{\dfrac{A}{\pi}}\geq0\)

i.e. \(A\geq0\)

A=0 represents a point circle since it's area is zero.

Hence, the domain of the function is:

[0,∞)