4 ' 9 ' 1 6 ' 2 5
2-9.2,
2
3
4 '
2-10. - 1 , 2 , - 3 , 4 , - 5 , . . .
{xn} ketma-ketlikni chegaralanganlikka tekshiring(l 1-16):
2-11 xn = ( - 1) ”
2-13. xn = —Inn.
2- 12. xn = n 3 + 2n.
2-14. x
2-15.
x n
= (—l ) n •
n
2-16, x„ = [
1
a g a r
n
=
2k
л/гГ a # a r n = 2/c + 1.
2-17. Agar {xn} va {yn} chegaralangan ketma-kertliklar bo‘lsa, u holda a)
{xn
+ yn}; b) {
xn -
y„}; c) {
x n
• yn) ketma-ketliklaming chegaralangan ekanligini
isbotlang.
2-18. Shunday lkkita chegaralangan ketma-ketlikka misol keltiringki,
ulaming nisbati chegaralanmagan bo‘lsin.
Quyidagi ketma-ketliklaming chegaralangan ekanligini isbotlang (19-22):
2-19. xn = л/n 2 + 1 - n.
2-20.
x n
=
In
(n + 1) -
In n.
2-25. xn = P2n, (n > 2) bu yerda P2n - birlik doiraga ichki chi2dlgan
muntazam 2n-burchakning perimetri.
ketlikni chegaralanganlikga, monotonlikka tekshiring.
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