# Find next two terms...

• Oct 11th 2011, 09:28 PM
Find next two terms...
-5,3,-2,1,-1,0,__,__?
360,180,120,90,__,__?

thanks
• Oct 12th 2011, 04:56 AM
skeeter
Re: Find next two terms...
Quote:

-5,3,-2,1,-1,0,__,__?
360,180,120,90,__,__?

what I see ...

1st sequence, note the differences:

8, 5, 3, 2, 1 ... looks like a Fibonacci sequence backwards with alternating signs.

2nd sequence:

(1)360, (1/2)360, (1/3)360, (1/4)360, ...

these are just sequences the author came up with so that you could play the "guess what I had in mind" game ... imho.
• Oct 12th 2011, 10:03 AM
Re: Find next two terms...
Quote:

Originally Posted by skeeter
what I see ...

1st sequence, note the differences:

8, 5, 3, 2, 1 ... looks like a Fibonacci sequence backwards with alternating signs.

2nd sequence:

(1)360, (1/2)360, (1/3)360, (1/4)360, ...

these are just sequences the author came up with so that you could play the "guess what I had in mind" game ... imho.

Thanks, skeeter. I *still* don't see the next two terms for the first sequence, though. Any more help? (my son's test is tomorrow, these are practice questions).
• Oct 12th 2011, 10:33 AM
skeeter
Re: Find next two terms...
look at the first "sequence" backwards ...

0, -1, 1 , -2, 3 , -5

ignore the signs for a moment ...

0, 1, 1, 2, 3, 5

except for the first two terms, each subsequent term is the sum of the two prior terms, then the signs were made to alternate.

to tell you the truth, I sort of believe the sequence "pivots" at 0 and just runs in the same manner with alternating signs

-5,3,-2,1,-1,0, 1, -1, 2, -3, 5 ...

as I stated earlier, this is not a mathematical sequence ... it's a "guess what I did" exercise.