Upload
florina-stefan
View
24
Download
1
Embed Size (px)
Citation preview
5/13/2018 aproximari - slidepdf.com
http://slidepdf.com/reader/full/aproximari 1/2
Problema propusa
-Marcu Stefan Florin-profesor Calarasi-
Enunt:
Aflati ( fara a folosi calculatorul ) , primele doua zecimale ale numaruluisin 1 . ( exprimare in radiani , nu in grade ) .
Solutie :
Folosind dezvoltarea in serii Taylor a functiei sin , avem :
sin x=!1
1*x-
!3
1*x 3 +
!5
1*x 5 -
!6
sin x
ε
*x 6 , unde xε ∈ (0,x) .
Luam x=1 si avem :
)!5
1
!3
1
!1
1
(1sin +−− = !6
sin 1ε
− unde 1ε ∈ (0,1) .
Deci )120
1
6
11(1sin +−− =
720
sin 1ε
≤720
1.
Avem120
1011sin − ≤
720
1 ⇔
720
605≤sin 1≤
720
607.
Efectuand impartirile avem :720
605=0,84027 si
720
607=0,8430 .
Deci , primele doua zecimale ale numarului sin 1 sunt 8 respectiv 4 .
5/13/2018 aproximari - slidepdf.com
http://slidepdf.com/reader/full/aproximari 2/2