What is the sum of the infinite geometric series? Negative 3 minus three-halves minus three-fourths minus three-eighths minus three-sixteenths minus ellipsis

Respuesta :

Answer:

[tex]S=-6[/tex]

Step-by-step explanation:

Sum Of A Geometric Series

Given a geometric series

[tex]a_1,\ a_1.r,\ a_1.r^2,\ a_1.r^3,...[/tex]

The sum of the infinite terms is given by

[tex]\displaystyle S_n=\frac{a_1}{1-r}[/tex]

The sum converges only if  

[tex]|r|<1[/tex]

We are given the series as a sum:

[tex]S=\displaystyle -3-\frac{3}{2}-\frac{3}{4}-\frac{3}{8}-\frac{3}{16}...[/tex]

Factoring by -3:

[tex]\displaystyle -3\left (1+ \frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}...\right )[/tex]

The expression in parentheses is a geometric series with  

[tex]a_1=1,\ r=1/2[/tex]

The sum can be computed by using the formula

[tex]\displaystyle S_n=\frac{1}{1-1/2}[/tex]

[tex]S_n=2[/tex]

So our expression becomes

[tex]S=(-3)(2)[/tex]

[tex]\boxed{S=-6}[/tex]

Answer:

D. -6

Step-by-step explanation:

on edge