Question

Determine o numero de termos da PA
(1/2,2,7/2,...,35)

Answer 1

Resposta:

a1=1/2

r=a3 - a2

r = 7/2 - 2

r = 3/2

an=35

n=?

35=1/2 +(n-1).3/2

35=1/2+3n/2-3/2

35=3n/2 - 1

35 +1=3n/2

36=3n/2

72=3n

n=72/3

n=24 termos