Question of ch5 , Q If 8n=4n-n2 find an

1.	Question of ch5 , Q If 8n=4n-n2 find an
Answer» We have given thatSum of the first n terms = 4n – n2⇒ Sn\xa0= 4n – n2Sn –1\xa0= 4(n – 1) – (n – 1)2= (4n – 4) – (n2\xa0+ 1 – 2n)= 4n – 4 – n2\xa0– 1 + 2n= 6n – n2\xa0– 5∴ nth term = Sn\xa0– Sn – 1= (4n – n2) – (6n – n2\xa0– 5)= 4n – n2\xa0– 6n + n2\xa0+ 5= 5 –2n.

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