- 1
- The function
εη(x)
is known as the variation in Y.
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- 2
- Don't confuse this with
`extremum'. The terminology is
standard, e.g. Gelfand and Fomin p.15, but can be confusing.
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- 3
- See
Blå
sjö
- The
Isoperimetric Problem for the history.
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