write a formula that produces the given terms of the sequence a_1= 1/8, a_2= -1/4, a_3= 1/2, a_4=-1, a_5=2

Question

amistre64 · Answer

Put everything in the same pants...like denominators:

+1/8
-2/8
+4/8
-8/8
+16/8

.... does this help?

amistre64 · Answer

y = -2(-x)/8 ?  nope.....

anonymous · Answer

umm...it needs to be written in "n" form lol i think....its an infinite sequence i know that

amistre64 · Answer

yeah....  I need to learn them better.  But, I can write a program that will spit out the numbers in that sequence :)

anonymous · Answer

ok, that'd be great :)

amistre64 · Answer

ack!!.... maybe I cant

anonymous · Answer

$$a_n = (-1)^n*2^n*1/8$$ I felt SO relieved after I got this. :P Btw, it starts at n=0.

anonymous · Answer

i thought it started at 1

anonymous · Answer

i get it now :)

anonymous · Answer

Sorry, if it starts with a_1 then it should be:$$a_n = (-1)^{n-1}*2^{n-1}*1/8$$

amistre64 · Answer

Are we allowed to use trig?

I had considered  2^n cos(pi(n-1)) / 8

anonymous · Answer

That doesn't quite work, the first term gives you something that isn't 1/8, but yours is very creative...

amistre64 · Answer

granted, but if the sequence starts at a_1 it could work...maybe....with a little luck :)   and thanx!