# analysis help

• Oct 6th 2009, 03:08 PM
friday616
analysis help
Find V(x-x^2, [-1,2]) and V(cos(4PIx), [0,1]).

I don't even know what this notation means...

Any help??
• Oct 8th 2009, 01:03 PM
Opalg
Quote:

Originally Posted by friday616
Find V(x-x^2, [-1,2]) and V(cos(4PIx), [0,1]).

I don't even know what this notation means...

Any help??

That is not a standard notation, so what follows is only a guess. I suspect that the V stands for variation. So the question is possibly asking for the total variation of the function over the given interval.

For example, the function \$\displaystyle x-x^2\$ increases from –1 to 1/2, and then decreases from 1/2 to 2. So its total variation over the interval [–1,2] is the amount that it increases between x=–1 and x=1/2, plus the amount that it decreases between x=1/2 and x=2.
• Oct 8th 2009, 03:11 PM
tonio
Quote:

Originally Posted by friday616
Find V(x-x^2, [-1,2]) and V(cos(4PIx), [0,1]).

I don't even know what this notation means...

Any help??

If you don't know how do you expect others will know? Go and find out and then tell us, though I'd guess it may mean the Variation of the given function in the given interval. Perhaps you guys are about to enter into Riemann-Stieltjes integral or stuff?

Tonio