Identify each sequence as arithmetic or geometric. Explain your answer, and write an explicit formula for the
sequence.
a. 14, 11, 8, 5, …

Respuesta :

Answer:

Arithmetic sequence

[tex]a_n=17-3n[/tex]

Step-by-step explanation:

We are given that a sequence

14,11,8,5,...

We have to identify sequence as arithmetic or geometric and write explicit formula for the sequence.

[tex]a_1=14[/tex]

[tex]a_2=11[/tex]

[tex]a_3=8[/tex]

[tex]d_1=a_2-a_1=11-14=-3[/tex]

[tex]d_2=a_3-a_2=8-11=-3[/tex]

[tex]d_3=a_4-a_3=5-8=-3[/tex]

[tex]d_1=d_2=d_3=-3[/tex]

When the difference of consecutive terms is constant then the sequence is arithmetic sequence.

Hence, the sequence is an arithmetic sequence.

[tex]a_n=a+(n-1)d[/tex]

substitute the values then we get

[tex]a_n=14+(n-1)(-3)=14-3n+3=17-3n[/tex]

Then, the explicit formula is given by

[tex]a_n=17-3n[/tex]