The function f(r) gives the circumference of a circle with radius r. It can be written in equation form as

f (r) = 2πr or f (r) = 2 (3.14) r.
What is f(6)?

To find f(6), we substitute 6 for r in the equation f(r) = 2πr:

f(6) = 2π(6)

Using the approximation 3.14 for π, we have:

f(6) = 2(3.14)(6)

Simplifying, we get:

f(6) = 37.68