siruri si serii in r

38
 9  Tema 2. Şiruri şi serii numerice. Aplicaţii Modul I. Şiruri numerice convergente în R. Serii numerice convergente Vom studia noţiunea fundamentală de “limită a unui şir numeric”, folosind rezultatele cunoscute din liceu (f ăr ă demonstraţii) şi unele completări importante. Definiţia 1. 1. Se numeste şir de numere reale orice func ţie f : N R cu f(n) notat  x n   R , unde n este rangul sau locul termenului în şir şi  x n este termenul general al şirului; notăm şirul prin (  x n ). 2. Pentru orice şir strict crescător spre (+) de numere naturale: n 0 <n 1 <...<n k <... şirul 1 k notat n k  x y = k N se numeşte subşir al şirului (  x n ). 3. Nu se confundă şirul (  x n ) care este o funcţie, cu mulţimea termenilor săi {  x 0 ,  x 1 , ...,  x n , ...}  R ; pentru un subşir avem: { 0 1 , ,..., k n n n  x x x , ...}  { x 0 , x 1 , ..., x n , ...}R . Un şir (  x n ) se numeşte şir constant dacă  x n = x 0 , n 0. Un şir (  x n ) se numeşte şir periodic dacă există k N a.î.  x n+k =  x n , nN ( f(n+k) = f(n), nN). 4. Un şir (  x n ) se numeşte şir staţionar dacă există n 0 cu n 0 N a.î. x n = x n0 , n n 0 (f(n) = f(n 0 )), n n 0 . Exemple 1.  x n = ( ) n 1 n , n1 are elementele –1, 2 1 , 3 1 , 4 1 ,... 2. 0 1 2 3 4 , , , , , 5 3 , 5 n  x x x x x n  x n < = are elemente:  x 0 , x 1 , x 2 , x 3 , x 4 , 3, 3, ..., 3, ... este un şir staţionar (are n 0 = 5, deci x n =3 pentru n 5). 3. (  x n ) dat prin: 1, 0, 2, 3, 1, 0, 2, 3, ... este şir periodic. 4.  x n = a R , n  N este şir constant. 5.  x n = ( ) 2 1 2 1 n + cu elementele: 0, 1, 0, 1, ... este un şir periodic. 6.  x n = n 2 1 , n 0 are subşirul 2 1 1 2 k n k  x + = cu mulţimea elementelor  + K K K K , 2 1 , , 2 1 , 2 1 , 2 1 , 1 , 2 1 , , 2 1 , 2 1 , 2 1 n 3 2 1 n 2 5 3  deci (  y k ) k 0 =( k n  x ) k 0 = 0 k 1 k 2 2 1 +       .

Upload: razvangutu

Post on 09-Apr-2018

236 views

Category:

Documents


0 download

TRANSCRIPT

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 1/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 2/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 3/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 4/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 5/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 6/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 7/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 8/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 9/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 10/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 11/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 12/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 13/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 14/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 15/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 16/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 17/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 18/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 19/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 20/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 21/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 22/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 23/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 24/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 25/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 26/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 27/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 28/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 29/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 30/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 31/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 32/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 33/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 34/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 35/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 36/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 37/38

8/7/2019 Siruri si serii in R

http://slidepdf.com/reader/full/siruri-si-serii-in-r 38/38