Question

a. Diameter, d = 2rd = 2r The formula using function notation is ; The value when r = 5r = 5 is ; The diameter of the circle is feet when the radius is feet. b. Area, A = πr2A = πr2 The formula using function notation is ; The value when r = 5r = 5 is ; The area of the circle is feet when the radius is feet. c. Circumference C = 2πrC = 2πr The formula using function notation is ; The value when r = 5r = 5 is ; The circumference of the circle is feet when the radius is feet.

Answer 1

Answer with explanation:

Given : The diameter of the circle = 2r , where r is the radius.

Function notation for diameter : $D(r)=2r$

If the value of r= 5 feet

Then , the diameter of the circle is feet = 2(5) feet = 10 feet

Hence,  the diameter of the circle is 10 feet when the radius is 5 feet.

Also, area of circle : $A=\pi r^2$ , where r is the radius .

Function notation for area : $A(r)=\pi r^2$

For r= 5 feet

$A(r)=\pi (5)^2$

$\Rightarrow\ A(r)=25\pi\text{ square feet}$

Hence, The area of the circle is $25\pi$ square feet when the radius is 5 feet.

Also, the circumference of circle = $2\pi r$

Function notation for circumference = $C(r)=2\pi r$

For r= 5 feet

$C(r)=2\pi (5)=10\pi \text{ feet}$

Hence, The circumference of the circle is $10\pi$ feet when the radius is feet.