Silvanus Phillips Thompson,
Calculus Made Easy
(1914)
“ MAXIMA AND MINIMA. One of the principal uses of the process of differentiating is to find out under what conditions the value of the thing differentiated becomes a maximum, or a minimum. This is often exceedingly important in engineering questions, where it is most desirable to know what conditions will make the cost of working a minimum, or will make the efficiency a maximum. ”
