A geometric progression is given as follows 5, 20, 80,... , find
a. The general term T(n)
b. The seventh term
c. m if T(n) = 1280
Thanks i am math idiot.
Geometric progressijon
2008-06-06 9:31 am
回答 (2)
2008-06-06 9:54 am
✔ 最佳答案
as follows:http://i299.photobucket.com/albums/mm309/lokwanshan/ScreenHunter_08Jun060152.gif
remember: no one is idiot
參考: me
2008-06-06 9:44 am
(a) the common ratio=20/5=80/20=4
first term = 5
T(n)=5*4^(n-1)
(b) seventh term=T(7)=5*4^(7-1)=(calculate by yourself)
(c) 5*4^(n-1)=1280
4^(n-1)=256
4^(n-1)=4^4
n-1=4
n=5
first term = 5
T(n)=5*4^(n-1)
(b) seventh term=T(7)=5*4^(7-1)=(calculate by yourself)
(c) 5*4^(n-1)=1280
4^(n-1)=256
4^(n-1)=4^4
n-1=4
n=5
收錄日期: 2021-05-01 16:07:49
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