Problem number 19 states, a naughty puppy grabs the end of a roll of toilet paper and walks away at a constant speed. Which of the functions below best describes the thickness y of the roll as a function of the unrolled part x? So first, let's look at the final y value of this roll of toilet paper. The puppy will not be able to unroll the tube, so the diameter of the tube is the minimum diameter of the roll. This diameter would occur at the end of the unrolling, so that would be the final diameter. And because the circumference of the roll decreases as more paper is pulled out, and the paper is pulled out at a constant rate, y must decrease slowly at the beginning and faster at the end. So something like this. So this is how our final graph should look. So the question asked us, which of the functions below best describes the thickness y of the roll as a function of the unrolled part x? The answer is this one, letter e.

puppy

toilet paper

thickness function

unrolling

rate of change