Question

If the sum of first n terms of an A.P. is given by Sn=4n^2-3n,then find the nth term of an A.P.

Answer 1

Sn=4n2-3n

Sn-1=4(n-1)2-3(n-1)

=4(n2-2n+1)-3n+3

=4n2-8n+4-3n+3

=4n2-11n+7

Sn-Sn-1=4n2-3n-(4n2-11n+7)

=4n2-3n-4n2+11n-7

=8n-7
hope it helps
have a gud day

Answer 2

Hey!!!
____________
Here is your answer
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sn=4n^2-3n
s1=4×1^2-3×1
=4-3=1
s2=4×2^2-3×2
=16-6=10
a=1
t2=s2-s1
=10-1
=9
d=t2-a
=9-1
=8
tn=1+(n-1)8
tn=1+8n-8
tn=8n-7
I hope it will help you!!!