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Prove-that-n-IN-1-0-t-sin-2n-lnt-dt-1-1-e-2pi-pi-0-e-2t-sin-2n-t-dt-




Question Number 194868 by Erico last updated on 17/Jul/23
Prove that ∀n∈IN  ∫^( 1) _( 0) t sin^(2n) (lnt)dt= (1/(1−e^(−2π) )) ∫^( π) _( 0) e^(−2t) sin^(2n) (t)dt
ProvethatnIN01tsin2n(lnt)dt=11e2π0πe2tsin2n(t)dt
Answered by witcher3 last updated on 17/Jul/23
ln(t)=−x  ⇒∫_0 ^∞ e^(−2x) sin^(2n) (x)dx  =Σ_(k≥0) ∫_(kπ) ^((k+1)π) e^(−2x) sin^(2n) (x)dx  x→kπ+t  =Σ_(k≥0) ∫_0 ^π e^(−2kπ−2t) sin^(2n) (kπ+t)dt  =Σ_(k≥0) e^(−2kπ) ∫_0 ^π e^(−2t) sin^(2n) (t)dt  =∫_0 ^π e^(−2t) sin^(2n) (t)dt.Σ_(k≥0) e^(−2kπ)   =(1/(1−e^(−2π) ))∫_0 ^π e^(−2t) sin^(2n) (t)dt
ln(t)=x0e2xsin2n(x)dx=k0kπ(k+1)πe2xsin2n(x)dxxkπ+t=k00πe2kπ2tsin2n(kπ+t)dt=k0e2kπ0πe2tsin2n(t)dt=0πe2tsin2n(t)dt.k0e2kπ=11e2π0πe2tsin2n(t)dt

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