Question

Use stigma notation to represent the dune of the first seven terms of the following sequence: -4, -6, -8, ...

Answer 1

7Σn=1 (-2n - 2)

Explanation:

Sigma notation:

The top number is stop at n = 7 (inclusive)

The bottom number is start at n = 1

The equation is the expression for each term in the sum

Find explicit formula

d = -2, a₁ = -4

-4 - 2(n - 1)

-4 - 2n + 2

-2n - 2

7 goes on top of Σ

n = 1 goes on the bottom of Σ

-2n - 2 goes to the right of Σ