SOLUTION: Find a10 for the sequence with a1 = 3 and r=2

Algebra.Com
Question 1094708: Find a10 for the sequence with a1 = 3 and r=2
Found 2 solutions by ikleyn, jim_thompson5910:
Answer by ikleyn(52787)   (Show Source): You can put this solution on YOUR website!
.
If it is the geometric progression with the first term 3 and the common ratio of 2,

then the 10-th term is  =  =  = 1536.


I see many problems AP and GP posted today . . .


On geometric progressions see introductory lessons
    - Geometric progressions
    - The proofs of the formulas for geometric progressions
    - Problems on geometric progressions
    - Word problems on geometric progressions
in this site, written specially for you.

Read them and become an expert in this area.



Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!

The nth term of any geometric is
a(n) = a1*r^(n-1)

In our case, a1 = 3 and r = 2 so we have
a(n) = 3*2^(n-1)

Now plug in n = 10
a(n) = 3*2^(n-1)
a(10) = 3*2^(10-1)
a(10) = 3*2^9
a(10) = 3*512
a(10) = 1536

The 10th term is 1536

RELATED QUESTIONS

Find the explicit formula for the geometric sequence with a1 = -3 and r =... (answered by jim_thompson5910)
Given two terms of the arithmetic sequence, a7=12 and a10=-9, find a1 and... (answered by Fombitz)
a1=1,a10=-19683,r=-3 (answered by fractalier)
1. Find the 25th term of the arithmetic sequence ‒7, ‒4, ‒1, 2, ... 2.... (answered by MathLover1,greenestamps)
find the indicate term correctly. a1=3/2, d=1/8,... (answered by ikleyn)
Use the formula for the general term (the nth term) of a geometric sequence to find the... (answered by ewatrrr)
ARITHMETIC SERIES - Sn=n/2(a1 + an) Find the sum of the terms of the following... (answered by Edwin McCravy)
Use the formula for the general term (the nth term) of a geometric sequence to find... (answered by stanbon)
For the arithmetic sequence with a1=3 and a20=117, find the common difference... (answered by Theo)