Chapter 9.1, Problem 1QCE

Consider the sequence 4, 6, 8, 10, 12,….

(a) If ${\left\{a_n\right\}}_{n=1}^{+\infty }$ denotes this sequence, then $a_1=\text{\_\_\_\_\_\_,}$ $a_4={\text{\_\_\_\_\_\_, and a}}_{\text{7}}=\text{\_\_\_\_\_\_}.$ The general term is $a_n=\text{\_\_\_\_\_\_}.$

(b) If ${\left\{b_n\right\}}_{n=1}^{+\infty }$ denotes this sequence, then $b_0=\text{\_\_\_\_\_\_,}$ $b_4={\text{\_\_\_\_\_\_, and b}}_8=\text{\_\_\_\_\_\_}.$ The general term is $b_n=\text{\_\_\_\_\_\_}.$