■等面単体の体積(その397)
超平面
−x+√5y+√10z=0
からそれぞれの点までの距離は,符号もつけて
P1(0,0,0,0):0
P2(2,0,0,0):−2/4
P3(3/2,(√5)/2,(√10)/2,0):6/4
P4(1,√5,0,0):4/4
P0(0,0,0,0)
P1(m,m√2,0,−h)
P2(m,m√2,0,3h)
P3(2m,0,0,2h)
P0P1^2=3m^2+h^2
P0P2^2=3m^2+9h^2
P0P3^2=4m^2+4h^2
P1P2^2=16h^2
P1P3^2=3m^2+9h^2
P2P3^2=3m^2+h^2
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P0(0,0,0,2h)
P1(m,m√2,0,−h)
P2(m,m√2,0,3h)
P3(2m,0,0,0)
P0P1^2=3m^2+9h^2
P0P2^2=3m^2+h^2
P0P3^2=4m^2+4h^2
P1P2^2=16h^2
P1P3^2=3m^2+h^2
P2P3^2=3m^2+9h^2
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P1P2=P2P3=P3P4=2
P1P3=P2P4=√6
P1P4=√6
より,
3m^2+h^2=16h^2→m^2=5h^2
3m^2+9h^2=4m^2+4h^2 (OK)
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[まとめ]hの与え方が等間隔ではなくなっている.
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