Page 16 - Math Grade 11 (Advance)

PROEUS DARA

n-l n-1
"'
an = a 1 + ..iJ bk = 2 + L,; 2k 1 2 2
~ = 2 + 2 · n(n- 1) = 2 + n - n = n - n + 2
2
k = l k = l
2
t SH an = n - n + 2 '1

t::JI t::J1 0 I 2
~tHS8 f\lt1 (an) lflS~9 n fHlilntt:ll115 an= n -n+2 '1
1
0 I f::::l '::1 Ql
n. n M 5 ~ 9 n t S f\l5 1 , 2, 5, 10, 17 ,. . . '1
I
"
""
2. t:iMSlt:Htmn n nti'liiHShlntS8 '1
0
u u u 4
I
0 • Q1 ..., C»
n. nruln~9 n &Sf\ln (an): 1, 2, 5, 10, 17, ...
I
mh an dl~g n tS~nttlrutt:12j (an) '1 ~n (bn) dldrutubrut:llti 1 tS~n (a )
11
1 I 1
ttl rums~ bn RMflttl1115 bn = an+ l- an '1 ~n (bn) : 1' 3' 5' 7 , ... '1 ~fi (bn) dl ~fi
I I I
snsttlrul:flsn9 1 nli 1 2hdrutuhnHM2 tsng bn = 1 +2(n-l) = 2n-l '1
4"' u .... u ....
n-1 n-1 n-l
thmg n2!2 tt:iQlS an= a + l:bk = 1+ 2:(2k-1) = 1+22:k-(n-1)
1
k=l k=I k=l
1 2 2
= 1+2·2n(n-l)-(n-l) = 1+n -n-n+l = 2-2n+n
2
t Sl g an = 2- 2n + n

0
2. t:iMSldruUn n ntlUtltShln (a,,)
"
""
u u u 4
1
mh Sn dldru\jntS~n (an) ~
I
n
2
sn = at+az+a3+ ... +an = 2:(2-2k+k )
k =I

12n 6 l 1 2
= 6- 6n(n + 1) + 6n(n + 1 )(2n + 1) = n(l2- 6n 6 + 2n + n + 2n + 1)
6

1 2
= -n(7- 3n + 2n )
6

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