SOLUTION: Write a formula that expresses the radius of a circle in cm, r, in terms of the circumference of the circle in inches, C. r= Write a formula that expresses the area of the ci

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Question 1122921: Write a formula that expresses the radius of a circle in cm, r, in terms of the circumference of the circle in inches, C.
r=
Write a formula that expresses the area of the circle in cm2, A, in terms of the radius of the circle in cm, r.
A=
Write a formula that expresses the area of the circle in cm2, A, in terms of the circumference of the circle in inches, C.
A=
Suppose the function f determines the area of the circle in cm2 given the circumference of the circle in inches, C. Write a function formula for f.
f(C)=


Answer by Theo(13342) About Me  (Show Source):
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Write a formula that expresses the radius of a circle in cm, r, in terms of the circumference of the circle in inches, C.

the formula for circumference of a circle is C = 2 * pi * r
C is the circumference, r is the radius.

if you solve this equation for r, you will get:
r = C / (2 * pi).

Write a formula that expresses the area of the circle in cm2, A, in terms of the radius of the circle in cm, r.

the formula for the area of a circle is A = pi * r^2.
A is the area and r is the radius.

Write a formula that expresses the area of the circle in cm2, A, in terms of the circumference of the circle in inches, C.

the formula for the circumference of a circle C = 2 * pi * r

the formula for the area of a circle is A = pi * r^2.

in the formula of C = 2 * pi * r, solve for r to get r = C / (2 * pi)

in the formula of A = pi * r^2, replace r with C / (2 * pi) to get:

A = pi * (C / (2 * pi)) ^ 2

Suppose the function f determines the area of the circle in cm2 given the circumference of the circle in inches, C. Write a function formula for f.

the function f determines the area of the circle in square centimeters, given the circumference of the circle in inches.

the formula for the circumference of the circle is C = 2 * pi * r.

solve this formula for r to get r = C / (2 * pi)

the formula for the area of the circle is A = pi * r^2.

replace r in this formula with C / (2 * pi) to get:

A = pi * (C / (2 * pi)) ^ 2.

now C is in inches and you want A in square centimeters.

the conversion factor from inches to centimeters is:

1 inch = 2.54 centimeters

therefore, if the circumference is in inches, you would multiply it by 2.54 to get the equivalent value in centimeters.

you formula for A in terms of C would become:

A = pi * (C / (2 * pi) * 2.54) ^ 2.

this could also be written as:

A = pi * (C / (2 * pi)) ^ 2 * 2.54 ^ 2.