■ファニャーノのレムニスケート等分公式(その27)
dx/(1−x^4)^1/2=dy/(1−y^4)^1/2
を一般化して
mdx/(1−x^4)^1/2=ndy/(1−y^4)^1/2
を考えたい.
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[1]du/(1−u^4)^1/2=dz/(1−z^4)^1/2の場合
u=−{(1−z^2)/(1+z^2)}^1/2とおく.
[2]du/(1−u^4)^1/2=2dz/(1−z^4)^1/2の場合
u=2z(1−z^4)^1/2/(1+z^4)
u=(−1+2z^2+z^4)/(1+2z^2−z^4)
とおく.
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