0711132人目の素数さん
2020/10/18(日) 13:04:44.28ID:ZEBeZlNg= 5a^4 + (1/x) (x-a)^2 (x^3 + 2ax^2 + 3aax + 4a^3)
= 5a^4 + (1/x) (x-a)^2 (x + 1.65062919144a) (x^2 + 0.34937080856ax + 2.423318344753aa)
ここに a = (1/2)^{2/5} = 0.757858283255199
x=a で極小 (5a^4 = 1.649384886)
x=0 で発散
x=-1 に零点
f(k) = 1 k < 5a^4
= 2 k = 5a^4,
= 3 k > 5a^4,