释义 |
Schwarz's Inequality
| (1) |
Written out explicitly
| (2) |
with equality Iff with a constant. To derive, let be aComplex function and a Complex constant such that for some and . Since ,
| (3) |
with equality when . Set
| (4) |
so that
| (5) |
Plugging (5) and (4) into (3) then gives | | | (6) |
| (7) |
| (8) |
so
| (9) |
Bessel's Inequality can be derived from this. ReferencesAbramowitz, M. and Stegun, C. A. (Eds.). Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables, 9th printing. New York: Dover, p. 11, 1972.Arfken, G. Mathematical Methods for Physicists, 3rd ed. Orlando, FL: Academic Press, pp. 527-529, 1985.
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