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anonymous
 one year ago
Does anyone know how to do this Sigma Notation question?
anonymous
 one year ago
Does anyone know how to do this Sigma Notation question?

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SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3ok. your common ratio (r) is? your first term (\(a_1\)) is? your number of terms (n) is?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I have absolutely no clue how to figure out those thing my teacher never taught me

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3So you can't answer any of the questions I asked?

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3what is this: \(\large\color{black}{ \displaystyle 2(2)^{n1} }\) when n=1?

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3\(\large\color{black}{ \displaystyle 2(2)^{n1} }\) when n=1: \(\large\color{black}{ \displaystyle2(2)^{11} =2(2)^0=2\cdot 1=2}\)

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3Ok, can you tell me what is \(\large\color{black}{ \displaystyle 2(2)^{n1} }\) when n=2?

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3plug in 2 instead of n....

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3ok, now do the same when n=3

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3So so frar your terms are: 2, 4, 8.... do you notice any pattern?

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3you multiply times 2 every time, is this correct?

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3Ok, and this number by which you multiply every time (if a sequence is like yours, that follows a multiplication pattern), is called "common ratio" and is denoted by letter r.

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3So, we can say that r=2

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3Now, what does your sequence start from, what is the first term?

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3so we can say that the first term is 2. \(a_1=2\)  (NOTATIONS) A first term is denoted by \(a_1\) Second term is denoted by \(a_2\) Third term is denoted by \(a_3\) any nth term is denoted by \(a_n\) 

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3And then your number of terms is 7 (i colored it in blue) \(\Large\color{black}{ \displaystyle \sum_{ n=1 }^{\color{blue}{7}} 2(2)^{n1} }\)

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3so, now, again, pliz answer my 3 questions that I asked in the very beginning.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0your common ratio (r) is? 2 your first term (a1) is? 2 your number of terms (n) is? 7

freckles
 one year ago
Best ResponseYou've already chosen the best response.0do you still need help on this ?

freckles
 one year ago
Best ResponseYou've already chosen the best response.0you can use the formula \[a_1 \cdot \frac{1r^{n}}{1r}\] and enter in all that info you and @solomonzelman found together

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3My power went off for a couple of hours due to a rail. I don't even think that "rail" is a good name for what happened... in any case; my apologies, and good luck!

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.3and the answers to my initial 3 questions are correct, good job.
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