フェルマーの最終定理の証明 (846ﾚｽ)
上下前次1-新
抽出解除 必死ﾁｪｯｶｰ(本家) (べ) 自ID ﾚｽ栞 あぼーん

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814: １３２人目の素数さん [] 09/10(水)03:24 ID:wdfOyVp6(1/3)
∫[0→π/2]( tan(x) )^(1/n) dx　　(n≧2)
∫_0^(π/2)?(tan(x))^(1/n) dx を求める。
t=?sin?^2 x=(sin(x))^2
?sin?^2 x=1-?cos?^2 x ?cos?^2 x=1-t
dt=2sin(x)cos(x)dx=2√t √(1-t) dx
dx=dt/(2√t √(1-t))=(t^(-1/2) (1-t)^(1/2))/2 dt
(sin(x))^(1/n)=(√t)^(1/n)=t^(1/2n) (cos(x))^(1/n)=(√(1-t))^(1/n)=(1-t)^(1/2n)
∫_0^(π/2)?(tan(x))^(1/n) dx=∫_0^(π/2)?( (sin(x))^(1/n))/( (cos(x))^(1/n) ) dx=∫_0^(π/2)?( t^(1/2n))/(1-t)^(1/2n) (t^(-1/2) (1-t)^(1/2))/2 dt

=1/2 ∫_0^(π/2)???t^(1/2n) (1-t)^(-1/2n) t?^(-1/2) (1-t)^(-1/2) ? dt
=1/2 ∫_0^(π/2)??t^(1/2n-1/2) (1-t)^(-1/2n-1/2) ? dt
=1/2 ∫_0^(π/2)??t^(1/2+1/2n-1) (1-t)^(1/2-1/2n-1) ? dt
=1/2 ∫_0^(π/2)??t^(1/2+1/2n-1) (1-t)^(1/2-1/2n-1) ? dt
(1/2) B(1/2+1/(2n), 1/2-1/(2n))
= (1/2) Γ( 1/2+1/(2n) ) Γ( 1/2-1/(2n) ) / Γ( 1/2+1/(2n) + 1/2-1/(2n) )
= (1/2) Γ(z) Γ(1-z) / Γ(1)
= (1/2) ( π/sin(πz) ) / 0！
= π/( 2 sin(πz) )
= π/( 2 sin(π/2+π/(2n)) )
= π/( 2 cos(π/(2n)) ).

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815: １３２人目の素数さん [] 09/10(水)03:24 ID:wdfOyVp6(2/3)
Δr↑=r↑(t+Δt)-r(t). |r↑|=Δs≒RΔθ.
R≒Δs/Δθ, Δx→0⇒Δs→0
1/R=lim[Δx→0])Δθ/Δs=dθ/ds
Δs=√((Δx)^2+(Δy)^2)=√((Δx)^2+(Δy)^2)/(Δx)^2 (Δx)^2 )=√(1+(Δy/Δx)^2 ) Δx
tan(Δθ)= tan(β-θ)=(tanβ-tanθ)/(1+tanβtanθ)=(y'(x+Δx)-y'(x))/(1+y'(x+Δx)y'(x))
Δθ≠tan(Δθ)=(y'(x+Δx)-y'(x))/(1+y'(x+Δx)y'(x))
Δθ/Δs=((y'(x+Δx)-y'(x))/(1+y'(x+Δx)y'(x)))/(√(1+(Δy/Δx)^2 )Δx)
=1/√(1+(Δy/Δx)^2 )?1/Δx?(y'(x+Δx)-y'(x))/(1+y'(x+Δx)y'(x))
=1/√(1+(Δy/Δx)^2 )?(y'(x+Δx)-y'(x))/Δx?1/(1+y'(x+Δx)y'(x))
1/R=dθ/ds=(lim)[Δx→0]Δθ/Δs
=1/√(1+(dy/dx)^2 )(d^2 y)/(dx^2 )1/(1+(dy/dx)^2 )
=((d^2 y)/(dx^2 ))/(1+(dy/dx)^2 )^(3/2)

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816: １３２人目の素数さん [] 09/10(水)03:26 ID:wdfOyVp6(3/3)
M(θ)=E[e^θX ]=∫_(-∞)^∞??e^θx f(x)dx?
M(θ)=E[e^θX ]=1/(√2π σ) ∫_(-∞)^∞??e^θx e^(-(x-μ)^2/(2σ^2 )) ? dx=1/(√2π σ) ∫_(-∞)^∞?e^(θx-(x-μ)^2/(2σ^2 )) dx
θx-(x-μ)^2/(2σ^2 )=1/(2σ^2 ) (2σ^2 θx-(x-μ)^2 )=-1/(2σ^2 ) (? (x-μ)?^2-2σ^2 θx )
=-1/(2σ^2 ) (? x?^2+μ^2-2μx-2σ^2 θx )
=-1/(2σ^2 ) (? x?^2-2(μ+σ^2 θ)x+μ^2 )
=-1/(2σ^2 ) ((x-(μ+σ^2 θ))^2-(μ+σ^2 θ)^2+μ^2 )
=-1/(2σ^2 ) ((x-(μ+σ^2 θ))^2-(μ^2+2μσ^2 θ+σ^4 θ^2 )+μ^2 )
=-1/(2σ^2 ) ((x-(μ+σ^2 θ))^2-(2μσ^2 θ+σ^4 θ^2 ) )
=-(x-(μ+σ^2 θ))^2/(2σ^2 )+μθ+(σ^2 θ^2)/2
M(θ)=1/(√2π σ) ∫_(-∞)^∞?e^(θx-(x-μ)^2/(2σ^2 )) dx
=1/(√2π σ) ∫_(-∞)^∞?e^((-(x-(μ+σ^2 θ))^2/(2σ^2 )+μθ+(σ^2 θ^2)/2) ) dx
=1/(√2π σ) e^(μθ+(σ^2 θ^2)/2) ∫_(-∞)^∞?e^((-(x-(μ+σ^2 θ))^2/(2σ^2 )) ) dx
t=(x-(μ+σ^2 θ))/(√2 σ) x=√2 σt+μ+σ^2 θ dx=√2 σdt
(x-(μ+σ^2 θ))^2/(2σ^2 )=((x-(μ+σ^2 θ))/(√2 σ))^2=t^2
-∞<x?∞ ⇒-∞<t?∞

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