For a finite sequence of non zero numbers, the number

[jnelson0612]

:-)

[jkewalramani]

I still don't get it. The question says the variations in sign is defined as the number of pairs of consecutive terms of the sequence for which the product is negative. I repeat, consecutive terms. If we look at the sequence with the terms written in a consecutive manner it reads; (-6, -4, -3, 1, 2, 5)

As such, according to me the answer should be 1 (-3 & 1) which i know is incorrect.

What my question is- how are we treating -3 & 4 , -6 & 5 etc as consecutive terms of this sequence?

[tim]

"consecutive terms" means terms that are next to each other AS ORIGINALLY WRITTEN, not some arbitrary re-ordering of the terms..

[jkewalramani]

I see, so the third pair is -6 & 1?

[RonPurewal]

I see, so the third pair is -6 & 1?

no.
first sign change: 1 to -3
second sign change: -3 to 2
third sign change: 5 to -4