Question

Which spreadsheet would be used to compute the first five partial sums o the arthmetic series? an=-5(n-1)+8

Answer 1

The nth term of the arithmetic series is given by

`a_n=-5(n-1)+8`

Now find the first five terms
`a_1, a_2, a_3, a_4, a_5:`

`a_1=-5(1-1)+8=8`

`a_2=-5(2-1)+8=3`

`a_3=-5(3-1)+8=-2`

`a_4=-5(4-1)+8=-7`

`a_5=-5(5-1)+8=-12`

Thus the first five terms of the series is
`8,3,-2,-7,-12.`

Now find the partial sum of the series:

`S_1=a_1=8`

`S_2=a_1+a_2=8+3=11`

`S_3=a_1+a_2+a_3=8+3-2=9`

`S_4=a_1+a_2+a_3+a_4=8+3-2-7=2`

`image`