Question

1.5
score: 16.3/19 answered: 17/19
question 18
the circumference c of a circle is a function of its radius by c(r)=2πr. express the radius of a circle as a function of its circumference. call this function r(c).
r(c)=
find r(26π).
r(26π)=
interpret the meaning.
when the radius is 26π, the circumference is r(26π).
when the circumference is 26π, the radius is r(26π).
question help: video

Explanation:

Step1: Solve for r in C = 2πr

$r=\frac{C}{2\pi}$, so $r(C)=\frac{C}{2\pi}$

Step2: Substitute C = 26π into r(C)

$r(26\pi)=\frac{26\pi}{2\pi}=13$

Answer:

$r(C)=\frac{C}{2\pi}$
$r(26\pi)=13$
When the circumference is 26π, the radius is r(26π).