Question Number 103177 by mohammad17 last updated on 13/Jul/20
$${Find}\:{the}\:{gineral}\:{form}\:{of}\:{the}\:{sequence}\:\langle\mathrm{2},−\mathrm{2},\mathrm{2},−\mathrm{2},…..\rangle? \\ $$
Answered by Dwaipayan Shikari last updated on 13/Jul/20
$$\mathrm{2}\underset{{n}=\mathrm{1}} {\overset{\infty} {\sum}}\left(−\mathrm{1}\right)^{{n}+\mathrm{1}} \\ $$
Commented by mohammad17 last updated on 13/Jul/20
$${thank}\:{you}\:{sir} \\ $$