Culegere de probleme de Analiz˘a numeric˘a
Culegere de probleme de Analiz˘a numeric˘a
Culegere de probleme de Analiz˘a numeric˘a
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Problema 5.0.15 Să se stabilească generalizarea formulei lui Leibniz prin calcul<br />
simbolic.<br />
Solut¸ie. Eh operator <strong>de</strong> translat¸ie ce are efect numai asupra luiu<br />
Eh operator <strong>de</strong> translat¸ie ce are efect numai asupra luiv<br />
∆hu(x)v(x) = u(x+h)v(x+h)−u(x)v(x) =<br />
= (EhEh −I)u(x)v(x)<br />
∆h = EE −I<br />
∆h operator <strong>de</strong> diferent¸ă ce are efect asupra lui u<br />
∆h operator <strong>de</strong> diferent¸ă ce are efect asupra lui v<br />
En = I +∆h ∆h = Eh −I<br />
∆h = ∆hEh +∆h<br />
m<br />
∆ m h = (∆hEh +∆h) m =<br />
∆ m h u(x)v(x) =<br />
∆ m h<br />
m<br />
j=0<br />
(a+b) [m,j] =<br />
j=0<br />
∆ j<br />
h ∆m−j<br />
h Ej<br />
h<br />
<br />
m<br />
∆<br />
j<br />
j<br />
hu(x)∆m−j h v(x+jh)<br />
m<br />
j=0<br />
<br />
m<br />
a<br />
j<br />
[m−j,h] b [j,h]<br />
[a,a+h,...,a+nh;f] = 1<br />
(fg)(a) =<br />
m<br />
i=0<br />
n!h n∆m h f(a)<br />
<br />
m<br />
∆<br />
i<br />
i hf(a)∆m−i h g(a+ih)<br />
Problema 5.0.16 Să se <strong>de</strong>monstreze formula <strong>de</strong> sumare prin părt¸i.<br />
a+mh <br />
x=a(h)<br />
<br />
<br />
u(x)∆hv(x) = u(x)v(x)<br />
Să se calculeze<br />
m<br />
xb x<br />
x=0<br />
(b > 0, b = 1),<br />
a+(m+1)h<br />
a<br />
−<br />
a+mh <br />
x=a<br />
v(x+h)∆hu(x)<br />
m<br />
v(x+h)∆hh(x)<br />
x=0<br />
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