Question

Rewrite each geometry formula using function notation. Use the same variables as the formula in your function. Evaluate each function when r=5 feet. Do not round; write answers in terms of pi, if necessary. Explain the meaning of the result.
a. Diameter, d=2r
The formula using function notation is _______; The value when r=5 is _______; The diameter of the circle is ______ feet when the radius is ________ feet.

b. Area, A=pi x r^2
The formula using function notation is _______; The value when r=5 is _______; The area of the circle is ______ feet when the radius is ________ feet.

c. Circumference C=2 x pi r

The formula using function notation is _______; The value when r=5 is _______; The Circumference of the circle is ______ feet when the radius is ________ feet.

Answer 1

Answer:

A) d(r) = 2r

Value when r = 5 is 10 ft.

diameter is 10 ft when the radius is 5ft

B) A(r) = πr²

Value when r = 5 is 25π ft²

Area is 25π ft² when radius is 5 feet

C) C(r) = 2πr

Value when r = 5 is 10π

Circumference is 10π when radius is 5 feet

Step-by-step explanation:

A) Using function notation, since d = 2r

d(r) = 2r

d(5) = 2(5)

d(5) = 10 feet

This means that the diameter is 10 ft when the radius is 5ft

B) Area = πr²

In function notation, its;

A(r) = πr²

When radius is 5 feet,

Area is; A(5) = π(5²) = 25π

It means Area is 25π ft² when radius is 5 feet

C) Circumference is 2πr

In function notation, it's;

C(r) = 2πr

When r = 5 feet,

Circumference is;

C(5) = 2π(5)

C(5) = 10π