the sum of first n terms of an AP is 4n× n +2n . find the n term of this AP
Anonymous:
to find first term put n=0
which is equal to 0
to find second term put n=2
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Answered by
5
to find first term put n=1
which is equal to =6
to find 2nd term put n=2
20=6+2nd term
thus 2nd term=14
and common difference =8
so it's nth term =6+(n-1)8
=8n-2
which is equal to =6
to find 2nd term put n=2
20=6+2nd term
thus 2nd term=14
and common difference =8
so it's nth term =6+(n-1)8
=8n-2
tq sooooo much
ur welcome varshu
Answered by
5
sum of n turms in AP = sn
sn= 4n²+2n
s1= 4.1²+2.1 =4+2=6
s2 = 4.2²+2.2=16+4=20
s3 = 4.3²+2.3 = 36+6=42
a1=s1=6
a2=s2-s1=20-6=14
a3=s3-s2=42-20=22
first term a=6
combie difference = d=a2-a1
14-6
d=8
then nth term = an
a+(n-1)d
6(n-1)8
6+8n-8
8n-2
sn= 4n²+2n
s1= 4.1²+2.1 =4+2=6
s2 = 4.2²+2.2=16+4=20
s3 = 4.3²+2.3 = 36+6=42
a1=s1=6
a2=s2-s1=20-6=14
a3=s3-s2=42-20=22
first term a=6
combie difference = d=a2-a1
14-6
d=8
then nth term = an
a+(n-1)d
6(n-1)8
6+8n-8
8n-2
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