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definiti prin una dintre posibilele formule ale termenului de rang n , sirul
1, -2, 3,-4,5......
1/3,1/2, 3/5, 2/3 , 5/7....


Răspuns :

a)  1, -2, 3,-4,5......
b)  1/3,1/2, 3/5, 2/3 , 5/7....

 

a)1,-2,3,-4,5.......2k+1, -2k,.........................

Pn = n(-1)^(n-1), n={1,2,3,4,5,..............}

b) 1/3, 1/2, 3/5, 2/3, 5/7, 3/4, 7/9, 4/5................

Pn = n/(n+2), n={1,2,3,4,5,6,............}