As it turns out my light summer reading (the type of literature we read is indeed inﬂuenced by the season) was not as light as it used to be
When Least is Best is a history of the mathematics of minima and maxima. It was rather entertaining and, of course, instructive.
I am, however, not sure who the intended target audience is. There is quite a bit of mathematics, i.e. lots of formulas. For a mathematician these should be trivial (and, I fear, boring?). For a layman they may be discouraging. Even though Nahin often takes little steps that you can easily follow he assumes some very solid prior knowledge in trigonometry. I have to admit, I would have loved to find an appendix reminding me of all the trigonometric functions and their relationships. There is no such thing. And that is a pity. To understand all the calculus you need the trigonometry. With this knowledge most things become trivial, ok, easy to follow. Without this knowledge you are just lost and have to trust the author blindly as he proceeds.
This dampens the potential enjoyment that this book may cause. As a consequence, I do not think that I was able to fully appreciate the different ways to ﬁnd a minimum (or the solution to related problems) that evolved over time. Some finer points of the history of the mathematics of extrema remained hidden to me.