Using data collected by zoologist Reto Zach, the work done by a crow to break open a whelk (large marine snail) can be estimated by the function

where H is the height (in meters) of the whelk when it is dropped.

(a) Find dW/dH.
(b) One can show that the amount of work is minimized when dW/dH = 0. Find the value of H that minimizes W.
(c) Interestingly, Zach observed the crows dropping the whelks from an average height of 5.23 m. What does this imply?

W = 1 + 20 H-0.93, H