面白い問題おしえて〜な 34問目

[0464 １３２人目の素数さん 2021/01/22(金) 07:46:56.06 ID:n9I3J2ea]

>>419

S(d) = √(dd-1) + dd{π/4 - arccos(1/d)},

S(d)/d → Max.

{S(d)/d} ' = -(1/dd)√(dd-1) -arccos(1/d) + π/4 = 0,

　d = 1.09316974498502
　S(d) = 0.88322158341066
　S(d)/d = 0.80794550659903