21/02/03 18:02:22.46 8ZOUzdCR.net
arctan(ax)/arctan(bx) = (a/b) + (a/b)(aa-bb){ -(1/3)x^2 + (1/45)(9aa+4bb)x^4 - (1/945)(135a^4 +72aabb +44b^4)x^6 + ････ }
a/b = 1.2500000125 のとき
aa - bb = 0.3600000128 aa
bb = 0.6399999872 aa
(a/b){1 - 0.12000000427(ax)^2 + 0.09248000288(ax)^4 - 0.075848354045(ax)^6 + ････ }
これより
ax = 0.24994774
x = 0.25