The light intensity (measured in lux) in a certain pond at point (x, y, z) is given by f(x, y, z) = e −x/2 + e −y/3 + e −z/4 . a south american electric eel is swimming in the pond along a path with position after t seconds given by the function c(t) = hx(t), y(t), z(t)i. suppose c(5) = h1, 0, 2i and c 0 (5) = h3, 9π, 2i. how fast is the light intensity increasing along the eel’s path after 5 seconds?