The sum of the first term n of
AP is un2+2nThen nithterm of this AP. .
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Answered by
1
Step-by-step explanation:
ANSWER
S
n
⇒
2
n
[2a+(n−1)d]=2n
2
+n
2
2a+(n−1)d
=2n+1
2a+(n−1)d=4n+2
2
2a
+(
2
n−1
)=2n+1
a+(
2
n−1
)d=2n+1......(i)
T
8
=a+7d....(ii)
comparing eq (i) and (ii)
2
n−1
=7
∴ n−1=14
n=15,
Putting n=15
a+7d=2×15+1
=30+1
T
8
=30
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