Question

Express the following geometric series in sigma notation.
1+3+9+27+..... (20 terms)

Answer 1

First. Determine if it's an arithmetic or geometric series.

Answer 2

\[\large \sum_{k = 0}^{19}(3)^k\]

Answer 3

You can check by plugging in k = 0 1 2 3 etc..

1 + 3 + 3^2 + 3^3 + ...............+ 3^{19}

Answer 4

nice

Answer 5

Thanks..