Question

How would i find the explicit formula for the arithmetic sequence -11,-3,5,12

Answer 1

Arithmetic Sequence Formula:

`a_n=a_1+(n-1)d`

We have:

`a_1=-11,\ a_2=-3,\ a_3=5,\ a_4=12,\ ...`

`d=a_(n+1)-a_n\to d=-3-(-11)=-3+11=8`

Substitute:

`a_n=-11+(n-1)(8)=-11+8n-8=8n-19`

Answer:
`a_n=8n-19`