■レムニスケートの幾何学(その105)

  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.

===================================

[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.

===================================