sn=3^n-1 find tn and 3 rd term of series
Answers
Answered by
3
Answer:
Given,
S
n
=
3
n
4
n
−3
n
⇒S
n
=(
3
4
)
n
−1
S
n−1
=(
3
4
)
n−1
−1
T
n
=S
n
−S
n−1
=(
3
4
)
n
−1−(
3
4
)
n−1
+1
=(
3
4
)
n−1
(
3
4
−1)
∴T
n
=
4
1
(
3
4
)
n
T
1
=
4
1
(
3
4
)
1
=
3
1
T
2
=
4
1
(
3
4
)
2
=
9
4
T
3
=
4
1
(
3
4
)
3
=
27
16
T
1
T
2
=
9
4
×
1
3
=
3
4
T
2
T
3
=
27
16
×
4
9
=
3
4
As
T
1
T
2
=
T
2
T
3
, given series is in G.P
Step-by-step explanation:
please thank it and mark me as brainliest. and also follow me
Answered by
0
Answer:
a3=18
Step-by-step explanation:
s1=a1= 3^1-1=2
s2=3^2-1=8
a2=s2-a1=8-2=6
s3=3^3-1
= 26
a3=s3-s2=26-8=18
Similar questions