Question

If Sn=n² find S1, S2 , a1,a2 show that an= 2n+1​

Answer 1

Answer:

s

n

=2n

2

+3n

T

n

=s

n

−s

n−1

=2n

2

+3n−2(n−1)

2

−3(n−1)

=2n

2

+3n−2n

2

+2n−2−3n+3

=3n−2+n+3

=4n+1

T

1

=4+1=5

T

2

=8+1=9

d=−T

1

+T

2

d=9−5=4

Step-by-step explanation:

1 like please