Determine whether the geometric series 192 + 48 + 12 + ... converges or diverges, and identify the sum if it exists.


A.) Converges: 768

B.) Diverges

C.) Converges; 64

D.) Converges; 256

Respuesta :

Answer:

D.) Converges; 256

Step-by-step explanation:

x0= 192

x1 = 48 = 192/4

x2 = 12 = 192/(4 x 4)

Therefore, this series can be written as:

[tex]x_n = \frac{192}{4^n}[/tex]

Applying limits at infinity:

[tex]\lim_{n \to \infty} x_n= \lim_{n \to \infty} (\frac{192}{4^n}) = \frac{192}{\infty}=0[/tex]

Since the terms of the series tend to zero, we can affirm that the series converges.

The sum of an infinite converging series is:

[tex]S=\frac{x_0}{1-r} \\S=\frac{192}{1-\frac{1}{4} }\\S=256[/tex]

Thus, the answer is D.) Converges; 256