Question

Sequences and series Question...Please help!!!
A sequence is defined by Un = 3n - 2.
a. Prove that the sequence is arithmetic. Hint: Find Un+1 - Un
b. Find U1 and d.
c. Find the 57th term.
d. What is the least term of the sequence which is greater than 450?

Answer 1

which part you have doubt with ?

Answer 2

Part i dont understand, all the others i know how to do.

Answer 3

a. sorry

Answer 4

A sequence is arithmetic if Un+1 - Un is constant.

Answer 5

what you got \(U_{n+1}\)as ??
could you find it ?

Answer 6

3n+1

Answer 7

so,U n+1 - Un =....??

Answer 8

that equals 3

Answer 9

what does the three mean?

Answer 10

since its constant, the sequence is arithmetic.
that Un+1 - Un is actually d = the common difference

Answer 11

A sequence is arithmetic if d = the common difference=Un+1 - Un is constant.

Answer 12

oh... ok i get it now. thnx a lot. i did figure out that d is the same as Un+1 -Un

Answer 13

welcome ^_^