Characterizations of inner product spaces by orthogonal vectors
Let X be a real normed space with unit closed ball B. We prove that X is an inner product space if and only if it is true that whenever x, y are points in ?B such that the line through x and y supports 22B then x?y in the sense of Birkhoff.
| Published in: | Journal of Function Spaces and Applications |
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| Main Authors: | , |
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2006-01-01
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| Online Access: | http://dx.doi.org/10.1155/2006/521425 |