Question Number 152437 by fotosy2k last updated on 28/Aug/21
Commented by fotosy2k last updated on 28/Aug/21
$${pls}\:{help} \\ $$
Answered by qaz last updated on 28/Aug/21
$$\underset{\mathrm{n}=\mathrm{1}} {\overset{\infty} {\sum}}\left(−\mathrm{1}\right)^{\mathrm{n}} \frac{\mathrm{1}}{\mathrm{3}^{\mathrm{n}} }=\frac{−\frac{\mathrm{1}}{\mathrm{3}}}{\mathrm{1}−\left(−\frac{\mathrm{1}}{\mathrm{3}}\right)}=−\frac{\mathrm{1}}{\mathrm{4}} \\ $$
Commented by fotosy2k last updated on 30/Aug/21
$${thank}\:{you} \\ $$