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.

Respuesta :

[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:

[tex]A=\pi r^2[/tex]

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:

[tex]r^2=\dfrac{A}{\pi}\\\\r=\sqrt{\dfrac{A}{\pi}}[/tex]

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

[tex]\sqrt{\dfrac{A}{\pi}}\geq0[/tex]

i.e. [tex]A\geq0[/tex]

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

Hence, the domain of the function is:

[0,∞)