■連続数のピタゴラス三角形(その19)

 m^2=2n^2+2n+1が成立すれば,

  (m+n+1)^2+(m+n+2)^2=(m+2n+2)

も成立するか?

(証)

左辺=m^2+n^2+1+2mn+2m+2n+(m^2+n^2+4+2mn+4m+4n)

=2m^2+2n^2+5+4mn+6m+6n

右辺=m^2+4n^2+4+4mn+4m+8n

左辺−右辺=m^2−2n^2+1+2m−2n≠0

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 m^2=2n^2+2n+1が成立すれば,

  (m+n)^2+(m+n+1)^2=(m+2n+1)

も成立するか?

(証)

左辺=m^2+n^2+2mn+(m^2+n^2+1+2mn+2m+2n)

=2m^2+2n^2+1+4mn+4m+4n

右辺=m^2+4n^2+1+4mn+2m+4n

左辺−右辺=m^2−2n^2+2m≠0

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

 m^2=2n^2+2n+1が成立すれば,

  (m+n)^2+(m+n+1)^2=(m+2n+2)

も成立するか?

(証)

左辺=m^2+n^2+2mn+(m^2+n^2+1+2mn+2m+2n)

=2m^2+2n^2+1+4mn+4m+4n

右辺=m^2+4n^2+4+4mn+4m+4n

左辺−右辺=m^2−2n^2−3≠0

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