Geometric Sequence & Series: Find the first 3 terms of the sequence for which, a sub 5 = -6. & r=-1/3

Question

Geometric Sequence & Series: Find the first 3 terms of the sequence for which,  a sub 5 = -6. & r=-1/3

anonymous · Answer

Use this formula to find your three terms. $$a_{n}=a_{1}\left( r \right)^{n-1}$$  We know $$a_{5}=-6                    $$ and $$r=-\frac{ 1 }{ 3 }$$   So, just plug in your values given to you with n=5, and you can find $$a_{1}$$

Then once you know that, you can find everything else.  Let me know if you get stuck.

anonymous · Answer

ok thank you! that helped allot and i just finished it

anonymous · Answer

Good for you.  Glad I could help.