The population of a local species of dragonfly can be found using an infinite geometric series where a1 = 36 and the common ratio is one half. Write the sum in sigma notation and calculate the sum that will be the upper limit of this population

Question

anonymous · Answer

Here are the answer choices if you need them to look at

hartnn · Answer

The general formula for n'th term of Geometric sequence is 
$\Large a_i = a_1 r^{i-1}$

here, a1 = 36 and r = 1/2 
just plug in!

hartnn · Answer

and for the 2nd part,
use this sum formula
$\Large S_\infty = \dfrac{a_1}{r-1}$

hartnn · Answer

sorry, that should be 
$\Large S_\infty = \dfrac{a_1}{1-r}$

anonymous · Answer

$$a _{i}= 36 ^{1/2-1}$$ is what you meant?

hartnn · Answer

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