Question

a formula da pa e pg

Answer 1

$PA~~\to~~~~ a_n=a_1+(n-1)\times r\\\\\\Sendo:\\\\a_n=ultimo~~termo;\\ a_1=1\°~termo;\\ n=n\°~~de~~ termos;\\r=raz\~ao.$



$PG~~\to~~~~ a_n=a_1\times q^{n-1}\\\\\\ Sendo:\\\\a_n=ultimo~~termo;\\ a_1=1\°~termo;\\ n=n\°~~de~~ termos;\\q=raz\~ao.$

Answer 2

PA
Termo Geral:
an = a1 + (n - 1) * r

Soma de termos:
Sn = $\frac{(a1+an)*n}{2}$

PG
Termo geral:
$an = a1* q^{n-1}$

Soma de termos:
$Sn = \frac{a1( q^{n}-1)}{q-1}$

Bons estudos!   ;-)