Question

Suppose that the radius r and the circumference C=2πr of a circle are differentiable functions of t. How do you write an equation that relates dC/dt to dr/dt?

Answer 1

C = 2pi r

C' = 2pi r'

Answer 2

i think they have the setup\[\frac{dC}{dt}=\frac{dC}{dr}\frac{dr}{dt}\]
but it all amounts to the same thing

Answer 3

@amistre64 The available answers are:
A) dr/dt = 2pi dC/dt
B) dC/dt =dr/dt
C) dC/dt = 2pir dr/dt
D) dC/dt = 2pi(dr/dt)

Answer 4

drop the fractional notation and stick with the prime notation ....

Answer 5

C' = 2pi r' is in there