Answer:
(a) -3125, 15625
(b)
[tex]a_n=-5a_{n-1}, \\n\geq 2 \\a_1=1[/tex]
(c)[tex]a_n=(-5)^{n-1}[/tex]
Step-by-step explanation:
The sequence [tex]a_n$ _{n=1}^\infty[/tex] is given as:
[tex]\{1,-5,25,-125,625,\cdots\}[/tex]
(a)The next two terms of the sequence are:
625 X -5 = - 3125
-3125 X -5 =15625
(b)Recurrence Relation
The recurrence relation that generates the sequence is:
[tex]a_n=-5a_{n-1}, \\n\geq 2 \\a_1=1[/tex]
(c)Explicit Formula
The sequence is an alternating geometric sequence where:
Therefore, an explicit formula for the sequence is:
[tex]a_n=1\times (-5)^{n-1}\\a_n=(-5)^{n-1}[/tex]