Question

Given the first term and the common difference of an arithmetic sequence how do you find the first five terms and explicit formula: a1= -38, d=-100?

Answer 1

`a_1=-38, a_2=-138, a_3=-238, a_4=-338, a_5=-438`
`a_n=62-100n`

Explanation:

To calculate the consecutive terms just add `d` to `a_1`, so you get:
`a_2=a_1+r=-38+(-100)=-138`
`a_3=a-2-100=-138-100=-238`
and so on

To find the formula just substitute `a_1` and `r` in
`a_n=a_1+(n-1)r`

`a_n=-38-100(n-1)=-38-100n+100=62-100n`