please give me full solution
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faizaankhanpatp3bt9p:
i know the answer but if only they allow me to write
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Here’s the solution
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gd job u are right infact
dude an=2-2n+3 cause An= a + (n-2)d and a=3 and d= -2
every thing is correct except the last in his
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HEYA !!!
HERE IS YOUR ANSWER
____________________________
Sn = 4n - n^2
If n = 1
●S1 = 4 × 1 - (1)^2 = 4 - 1 = 3 (Ans)
Therefore, a1 = 3
If n = 2
●S2 = 4 × 2 - (2)^2 = 8 - 4 = 4 (Ans)
Since, an = Sn - Sn-1
●a2 = S2 - S1 = 4 - 3 = 1 (Ans)
If n = 3
S3 = 4 × 3 - (3)^2 = 12 - 9 = 3
●Therefore, a3 = S3 - S2 = 3 - 4 = -1 (Ans)
If n = 9
S9 = 4 × 9 - (9)^2 = 36 - 81 = - 45
If n = 10
S10 = 4 × 10 - (10)^2 = 40 - 100 = - 60
a10 = S10 - S9
● a10 = - 60 - (- 45) = - 60 + 45 = - 15 (Ans)
● nth term or an = Sn - Sn-1
= 4n - n^2 - 4 (n - 1) - (n - 1)^2
= 4n - n^2 - ( - n^2 + 6n - 5)
= 4n - n^2 + n^2 - 6n + 5
= 5 - 2n (Ans)
___________________________
# GUDIYA
HOPE IT HELPS !!! ☺☺✌✌
KHUSH REH ✋✋
HERE IS YOUR ANSWER
____________________________
Sn = 4n - n^2
If n = 1
●S1 = 4 × 1 - (1)^2 = 4 - 1 = 3 (Ans)
Therefore, a1 = 3
If n = 2
●S2 = 4 × 2 - (2)^2 = 8 - 4 = 4 (Ans)
Since, an = Sn - Sn-1
●a2 = S2 - S1 = 4 - 3 = 1 (Ans)
If n = 3
S3 = 4 × 3 - (3)^2 = 12 - 9 = 3
●Therefore, a3 = S3 - S2 = 3 - 4 = -1 (Ans)
If n = 9
S9 = 4 × 9 - (9)^2 = 36 - 81 = - 45
If n = 10
S10 = 4 × 10 - (10)^2 = 40 - 100 = - 60
a10 = S10 - S9
● a10 = - 60 - (- 45) = - 60 + 45 = - 15 (Ans)
● nth term or an = Sn - Sn-1
= 4n - n^2 - 4 (n - 1) - (n - 1)^2
= 4n - n^2 - ( - n^2 + 6n - 5)
= 4n - n^2 + n^2 - 6n + 5
= 5 - 2n (Ans)
___________________________
# GUDIYA
HOPE IT HELPS !!! ☺☺✌✌
KHUSH REH ✋✋
ya in the pic its wrong i told cause thats not me
XD never mind everyone gets confused even experts
Ya I did not add at the last
its ok mistakes happens
where u from ria
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