This question legitimately confuses me.

I found that the formula for a geometric sequence is An=1800 x 0.9^(n-1)

How does one calculate the maximum value from that, however?

I do not understand how there is a maximum value for geometric sequences.

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- Jun 12th 2012, 11:13 PMFloofyGeometric Sequences - How to find maximum value
This question legitimately confuses me.

I found that the formula for a geometric sequence is An=1800 x 0.9^(n-1)

How does one calculate the maximum value from that, however?

I do not understand how there is a maximum value for geometric sequences. - Jun 12th 2012, 11:39 PMbiffboyRe: Geometric Sequences - How to find maximum value
I think you mean a value which the sum of the sequence approaches but never reaches, called the sum to infinity. The formula ia a/(1-r)

So in your case a=1800 and r=0.9 so sum to infinity =1800/0.1 =18000. r has to be between -1 and +1 for a sequence to have a sum to infinity. - Jun 14th 2012, 11:16 PMrichard1234Re: Geometric Sequences - How to find maximum value
The maximum value of $\displaystyle a_n$ is simply the first term (assumed to be $\displaystyle a_1 = 1800$), because all proceeding terms get smaller.