Question 567832
<font face="Times New Roman" size="+2">


The sum of an arithmetic sequence is given by:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ S_n\ =\ \frac{n(a\ +\ l)}{2}]


Where *[tex \Large n] is the number of terms, *[tex \Large a] is the first term, *[tex \Large l] is the last term, and *[tex \Large S_n] is the sum of *[tex \Large n] terms.


Plug in the given values of *[tex \Large n], *[tex \Large l], and *[tex \Large S_n] and then solve for *[tex \Large a]


Once you have the value for *[tex \Large a], you can use that to find *[tex \Large d], the common difference because the *[tex \Large n]th term is given by:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ A_n\ =\ a\ +\ (n\,-\,1)d]


Plug in the values you know for *[tex \Large A_n], *[tex \Large a], and *[tex \Large n], then solve for *[tex \Large d].


Finally, calculate:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ a\ +\ 0d]


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ a\ +\ d]


and


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ a\ +\ 2d]


John
*[tex \LARGE e^{i\pi} + 1 = 0]
My calculator said it, I believe it, that settles it
<div style="text-align:center"><a href="http://outcampaign.org/" target="_blank"><img src="http://cdn.cloudfiles.mosso.com/c116811/scarlet_A.png" border="0" alt="The Out Campaign: Scarlet Letter of Atheism" width="143" height="122" /></a></div>
</font>