A recursive rule for an arithmetic sequence is a1=4;an=an−1−3 . What is the explicit rule for this sequence? Enter your answer in the box. an=

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Answer:

The explicit rule for the arithmetic sequence is given by:

[tex]a_n = a_1+(n-1)d[/tex]       ......[1]

where,

[tex]a_1[/tex] is the first term

n is the number of terms and

d is the common difference for two consecutive terms.

As per the statement:

A recursive rule for an arithmetic sequence is:

[tex]a_1 = 4[/tex]

[tex]a_n = a_{n-1}-3[/tex]

The recursive formula for the arithmetic sequence is given by:

[tex]a_n = a_{n-1}+d[/tex]

then;

On comparing we get;

d = -3

Substitute the given values in [1] we have;

[tex]a_n = 4+(n-1)(-3)[/tex]

⇒[tex]a_n = 4 -3n+3 = 7-3n[/tex]

Therefore, the explicit rule for this sequence is, [tex]a_n = 7 -3n[/tex]