(In reply to Way without calculus?
I agree the proper category is calculus.
However, there is a solution requiering neither the use of the series nor the explicit calculation of values- just checking the sign of the derivative of a certain function.
Calculus- yes; calculation - no.
Did I disclose too much?
Rem: a "double negative" grammar error corrected.
Edited on April 30, 2016, 3:35 am