Question

Encontre o termo geral da PG
A) PG ( 1,5...)
B) PG ( 2,7...)
C) PG ( 3,5...)
D) PG ( 1,7...)

Answer 1

a) a1 = 1
a2 = 5
q = 5
an = a1 . q^n-1
an = 1 . 5^n-1
an = 5^n-1

b)a1 = 2
a2 = 7
q = a2/a1
q = 7/2
q = 3,5
an = a1 . q^n-1
an = 2 . 3,5^n-1

c) a1 = 3
a2 = 5
q = a2/a1
q = 3/5
q = 0,6
an = a1 . q^n-1
an = 3 . 5^n-1

d) a1 = 1
a2 = 7
q = a2/a1
q = 7/1
q = 7
an = a1 . q^n-1
an = 1 . 7^n-1
an = 7^n-1