Respuesta :

Answer:

Please check the explanation.

Step-by-step explanation:

Given the sequence

[tex]40,\:10,\:\frac{5}{2},\:\frac{5}{8}[/tex]

A geometric sequence has a constant ratio 'r' and is defined by

[tex]\:a_n=a_0\cdot r^{n-1}[/tex]

Computing the ratios of all the adjacent terms

[tex]\frac{10}{40}=\frac{1}{4},\:\quad \frac{\frac{5}{2}}{10}=\frac{1}{4},\:\quad \frac{\frac{5}{8}}{\frac{5}{2}}=\frac{1}{4}[/tex]

The ratio of all the adjacent terms is the same and equal to

[tex]r=\frac{1}{4}[/tex]

Thus, the given sequence is a geometric sequence.

As the first element of the sequence is

[tex]a_1=40[/tex]

Therefore, the nth term is calculated as

[tex]\:a_n=a_0\cdot r^{n-1}[/tex]

[tex]a_n=40\left(\frac{1}{4}\right)^{n-1}[/tex]

Put n = 5 to find the next term

[tex]a_5=40\left(\frac{1}{4}\right)^{5-1}[/tex]

[tex]a_5=40\cdot \frac{1}{4^4}[/tex]

[tex]a_5=\frac{40}{4^4}[/tex]

   [tex]=\frac{2^3\cdot \:5}{2^8}[/tex]

[tex]a_5=\frac{5}{2^5}[/tex]

[tex]a_5=\frac{5}{32}[/tex]

now, Put n = 6 to find the 6th term

[tex]a_6=40\left(\frac{1}{4}\right)^{6-1}[/tex]

[tex]a_6=40\cdot \frac{1}{4^5}[/tex]

[tex]a_6=\frac{40}{4^5}[/tex]

    [tex]=\frac{2^3\cdot \:5}{2^{10}}[/tex]

[tex]a_6=\frac{5}{2^7}[/tex]

[tex]a_6=\frac{5}{128}[/tex]

Thus, the next two terms of the sequence 40, 10, 5/2, 5/8... is:

  • [tex]a_5=\frac{5}{32}[/tex]
  • [tex]a_6=\frac{5}{128}[/tex]