Question

find nth partial sum of the arithmetic sequence
an= 3n+2
n=10

Answer 1

\[\sum_{n=0}^{10}(3n+2)\]
\[3\sum_{n=0}^{10}n+\sum_{n=0}^{10}2\]

Answer 2

\[3\frac{n(n+1)}{2}+2n\]
if i recall correctly

Answer 3

Use the variation on the Gauss formula\[s=\frac{n}{2}\left[ 2a _{1}+(n-1)d \right]\]where a1=3(1)+3=5 is the first term
n=10 is the number of terms, and
d=3 is the common difference of the arth. series

Answer 4

that might only be from n=1,2,3 ....

Answer 5

my set up that is since n=0 results in 0

Answer 6

yes, you are correct, my assumption is pos. integers for domain

Answer 7

either way will work
\[3\times \frac{10\times 11}{2}+20\]