What is the formula for the arithmetic sequence if the sum of the same sequence is given by Sn = 2n + 3n2
?
Answers
Answered by
3
Answer:
Sn =3n^2+2n
n=1 a=3+2=5
n=2 a1+a2=3×2×2+2×2=16
a1 =5 a2=16-5=11
5 11
s3 =a1+a2+a3= 3×9+2×3 =33
a3=33-16=17
5 1 1 17 23 ----
a=5 d=6
an=a+(n-1)d
=5+(n-1)6=6n-1
The required answer is 6n-1
Similar questions