Expand menu menu_open Minimize Start chapters Home History history History expand_more
{{ item.displayTitle }}
navigate_next
No history yet!
Progress & Statistics equalizer Progress expand_more
Student
navigate_next
Teacher
navigate_next
{{ filterOption.label }}
{{ item.displayTitle }}
{{ item.subject.displayTitle }}
arrow_forward
No results
{{ searchError }}
search
menu_open
{{ courseTrack.displayTitle }}
{{ statistics.percent }}% Sign in to view progress
{{ printedBook.courseTrack.name }} {{ printedBook.name }}
search Use offline Tools apps
Login account_circle menu_open

Writing and Using Explicit Rules for Geometric Sequences

Writing and Using Explicit Rules for Geometric Sequences 1.13 - Solution

arrow_back Return to Writing and Using Explicit Rules for Geometric Sequences

The first three elements in the geometric sequence are a1a_1, a2a_2 and a3a_3. We can determine them by substituting 1,21,\, 2 and 33 instead of nn in the formula an=35n1.a_n = 3\cdot 5^{n-1}.

nn 35n13\cdot 5^{n-1} ana_n
1{\color{#0000FF}{1}} 35113\cdot 5^{{\color{#0000FF}{1}}-1} 33
2{\color{#0000FF}{2}} 35213\cdot 5^{{\color{#0000FF}{2}}-1} 1515
3{\color{#0000FF}{3}} 35313\cdot 5^{{\color{#0000FF}{3}}-1} 7575

The sequence starts with 33, 1515, and 75.75.