PDA

View Full Version : An integral inequality: Source?


philosophking
Mar20-05, 07:29 PM
I know this is probably a gross generalization of what the actual inequality states, but I'm wondering if someone can tell me the origin of this integral inequality (or something resembling it :/ ):

|\int f(x)| \leq \int|f(x)|

This is my first time using latex, so I hoped that turned out ok. Any suggestions on that too would be appreciated! Thanks.

DoubleMike
Mar20-05, 07:45 PM
I don't understand your question...

the left side just takes the absolute value of the area under f(x), which could well be negative. As for the right side, it will count a negative f(x) as positive... if it's applied to a velocity function, it would give the total distance travelled rather than displacement for example.

Crosson
Mar20-05, 07:47 PM
|\int f(x)| \leq \int|f(x)|

This is not a terribly interesting equality, I am sure that you could form a proof. I can only guess that you are trying to discuss the cauchy-schwarz inequality:

http://mathworld.wolfram.com/SchwarzsInequality.html

Which is reasonably famous but very uninteresting.

Data
Mar20-05, 08:16 PM
It's just an application of the triangle inequality.