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Everything about Oscillation Mathematics totally explained

In mathematics, oscillation is the behaviour of a sequence of real numbers or a real-valued function, which doesn't converge, but also doesn't diverge to +∞ or -∞; that is, oscillation is the failure to have a limit, and is also a quantitative measure for that.
   Oscillation is defined as the difference (possibly ∞) between the limit superior and limit inferior. It is undefined if both are +∞ or both are -∞ (that is, if the sequence or function tends to +∞ or -∞). For a sequence, the oscillation is defined at infinity, it's zero if and only if the sequence converges. For a function, the oscillation is defined at every limit point in [-∞,+∞] of the domain of the function (apart from the mentioned restriction). It is zero at a point if and only if the function has a finite limit at that point.

Examples

  • 1/x has oscillation ∞ at x = 0, and oscillation 0 at other finite x and at -∞ and +∞.
  • sin (1/x) has oscillation 2 at x = 0, and 0 elsewhere.
  • sin x has oscillation 0 at every finite x, and 2 at -∞ and +∞.
  • The sequence 1, −1, 1, −1, 1, −1, ... has oscillation 2.
In the last example the sequence is periodic, and any sequence that's periodic without being constant will have non-zero oscillation. On the other hand, non-zero oscillation doesn't imply periodicity.
   Geometrically, the graph of an oscillating function on the real numbers follows some path in the xy-plane, without settling into ever-smaller regions. In well-behaved cases the path might look like a loop coming back on itself, that is, periodic behaviour; in the worst cases quite irregular movement covering a whole region.

Generalizations

More generally, if f : XY is a function from a topological space X into a metric space Y, then the oscillation of f is defined at each xX by » omega(x) = infleft

Further Information

Get more info on 'Oscillation Mathematics'.


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