Question

Find S7 when sn = ( -1 ) n

Answer 1

Okay, here we have this:

Considering the provided sequence, let's find the requested term, so we obtain the following:

$\begin{gathered} S_n=(-1)^n \\ S_7=(-1)^7 \\ S_7=-1 \end{gathered}$

Finally we obtain that S₇ is equal to -1.