Question 1152199
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<pre>

First term is -2;  the common ratio is (-4).


The general term  {{{a[n]}}} = -{{{2*(-4)^(n-1)}}}.


So you need find "n" from the equation


    -{{{2*(-4)^(n-1)}}} = 2048.


It gives


    {{{(-4)^(n-1)}}} = {{{2048/(-2)}}} = -1024 = {{{(-4)^5}}}.


Hence,  n-1 = 5  and  n = 5+1 = 6.    <U>ANSWER</U>
</pre>

Solved.