......complex analysis.....
if , f(α,n,x)=(d^( n) /dx^n )(α^x ) , x∈C
α∈C−{0} , n∈C−Z^− ∪{0}
and g(n,x)=∫_0 ^( 1) f(α,n,x)dα
then find the value of ...
Ω=((Im(g(i,0)))/(Re(Γ(i))))
solution:
g(n,x)=∫_0 ^( 1) (d^( n) /dx^(n ) )(α^x )dα
=∫_0 ^( 1) (d^( n) /dx^n )(e^(xln(α)) )dα .....⟨∗⟩
(d^( n) /dx^n )(e^(xln(α)) )=(ln(α))^n α^x
⟨∗⟩→ ...g(n,x)=∫_0 ^( 1) (ln(α))^n α^x dα
=_(α=e^(−y) ) ^(ln(α)=−y) ∫_0 ^( ∞) (−1)^n y^( n) e^(−yx) e^(−y) dy
=(−1)^n ∫_0 ^( 1) y^n .e^(−y(1+x)) dy
=^(y(1+x)=t) (−1)^n ∫_0 ^( 1) ((t^n e^(−t) )/((1+x)^(n+1) ))dt
=e^(inπ) .(1/((1+x)^(n+1) )) .Γ(n+1)
g(i,0)=e^(−π) .i.Γ(i) ......⟨∗∗⟩
Γ(i)∈C ⇒ Γ(i)=Re(Γ(i))+Im(Γ(i))
⟨∗∗⟩→ ... g(i,0)=e^(−π) .i.[Re(Γ(i))+Im(Γ(i))]
∴ Ω=((e^(−π) Re(Γ(i)))/(Re(Γ(i)))) =e^(−π) ...✓✓
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