Comments | futurebird: just checking

futurebird

just checking

Mar 16, 2007 20:22

f(x) = sin(x) + sin(x*sqrt(2)) has no fundamental period.

Right?

math

Comments 7

detroitfather March 17 2007, 01:22:11 UTC

You want the mathematician answer or the engineer answer?

( ... )

Typo ... detroitfather March 17 2007, 01:24:10 UTC

That should have read: So, if you and I as friends can agree ...

futurebird March 17 2007, 13:09:26 UTC

So, you and I as friends, can agree to call sqrt(2) = 1.4

Only if you make that a WAVY equal sign!

This all makes me so nervous.

detroitfather March 17 2007, 13:25:15 UTC

sqrt(2) ≈ 1.4

Works for me.

So, in summary, your function has various values of x for which it is "approximately periodic" ... If you are willing to make the even rougher assumption that sqrt(2) ≈ 1.5, then you see that it has an even shorter (smaller) "approximate fundamental period".

Or, if you wish to go in the other direction (i.e., less deviation from mathematical exactness), you can say sqrt(2) ≈ 1.4142 (or any other rational approximation), and then the "approximate fundamental period" will be much longer (larger).

Thread 6

war4l March 17 2007, 05:01:33 UTC

i'm failing a "math for designers" class and you're on some engineering tip?
WOW!
::FAINTS::