Question

a fisherman hooks a trout and reels in his line at 4in/s. Assume the tip of the fishing rod is 12ft above the water and the fish is pulled horizontally directly towards the fisherman. Find the horizontal speed of the fish when it is 20 ft from the fisherman.

Answer 1

if i read the problem correctly that is a picture
then by pythagoras we see that
\[y^2+12^2=x^2\] taking derivatives we get
\[2yy'=2xx'\] you are told that \(x'=4\) your job is to solve for \(y'\) when \(x=20\)