Răspunsuri

2014-10-02T22:07:59+03:00

termenul de mijloc al sirului este al 1002-lea termen

a1,a2,a3,a4,...............a1002 = 2003 ............a2003

a1,(a1+1),(a1+2),(a1+3),.....(a1+1001 = 2003)⇒                                       a1= 1002   a2003=a1+2002 =1002+2002 =3004

S = 1002 +1003 +1004 +.............+3004

daca S1 = 1+2+3+........3004 = 3004×3005/2 = 4513510

 S2= 1+2+3+......+1001 =1001×1002/2 = 501501     ⇒   

S = S1 - S2 = 4012009