My test has five question. But it looks very differnt from what we just did :(

Question

anonymous · Answer

@ganeshie8

ganeshie8 · Answer

ha

anonymous · Answer

FLVS?

anonymous · Answer

Identify whether the series $$\sum_{i=1}^{\infty} $$ is a convergent or divergent geometric series and find the sum, if possible.

anonymous · Answer

and yes flvs

anonymous · Answer

yep. they always seem to do that. The tests have questions that u never see in the lesson. good luck Lesha.

ganeshie8 · Answer

@Jhannybean

anonymous · Answer

@kjuchiha ya ikr ! i just did the lesson and im like wow this is easy . and now the test im lik woaah this looks totally different then the lesson . and thankyouu (:

jhannybean · Answer

Where is your an?? I just see the starting of the series..

anonymous · Answer

what kind of series is that? dont have nth term

anonymous · Answer

oops soorryy.
Identify whether the series $$\sum_{i=1}^{\infty}16(5)^{i-1}$$ is a convergent or divergent geometric series and find the sum, if possible.

jhannybean · Answer

Oh okay. From the geometric series $$|r| < 1 $$ for the series to be convergent.is r< 1?

jhannybean · Answer

$$\large \sum_{i=1}^{\infty}a_{1}r^{i-1}$$

jhannybean · Answer

$$\large \sum_{i=1}^{\infty}(16)(5)^{i-1}$$

jhannybean · Answer

Match up the terms to the definition of geometric series to help you out.

anonymous · Answer

ok so what does convergent and divergent mean ?

jhannybean · Answer

convergent means the behavior of the function goes to 0 as the function gets infinitely large and diverges means as  the function approaches an infinite limit, the function will take on a very large value.

anonymous · Answer

okk . so how would i solve this problem ?

jhannybean · Answer

Observe that the formula for a geometric series $$\large \sum_{i=1}^{\infty}a_{1}r^{i-1}$$is where $\large a_{1}$ is your first term and $\large r$ is your ratio. Your equation is $$\large \sum_{i=1}^{\infty}16(5)^{i-1}$$ where $\large a_{1}= 16$ and $\large r=5$. In order for this seriesto be convergent, the $\large |r|$ has to be $\large < 1$. in this case $\large r = 5$ and therefore is not less than 1. Therefore the series is divergent. http://www.purplemath.com/modules/series5.htm