Question

4. The first two numbers in a sequence are 3, 9.

a. If this is an arithmetic sequence, what are the next 2 terms?
b. Write the a definition for the nth term of the sequence:

Answer 1

234567

Explanation:

Answer 2

AP equation:

• 
  `t_n=t_1+(n-1)d`

Based on the first two terms, we have:

• 
  `t_1=3,\\t_2=9\\d=9-3=6`

The equation is:

• 
  `t_n=3+(n-1)*6=3+6n-6=6n-3`

Next two terms are:

• 
  `t_3=6*3-3=15\\t_4=6*4-3=21`