From the sequence 9, 16, 23, 30, 37, 44… solve the following.

Question

1. What is the 58th term of the given sequence?
2. What is the sum of the first 350 terms of the given sequence?

Answer 1

1) the common difference is D=7

A1=9

f(n) = A1 + (n-1)*D

= 9 + (n-1)*7

= 9+ 7n-7

= 7n + 2

f(58) = 7*58+2 = 408

2)

f(350) = 7*350+2 = 2452

Sn = N/2 ( A1+An)

= 350/2 ( 9+ 2452)

= 430765