Article
Keywords:
inner product space; norm derivative $\rho ^{\prime }_{\pm }$; heights
Summary:
Generalizing a property of isosceles trapezoids in the real plane into real normed spaces, a couple of characterizations of inner product spaces (i.p.s) are obtained.
References:
[1] Alsina C., Guijarro P., Tomás M. S.:
On heights in real normed spaces and characterizations of inner product structures. Jour. Int. Math. & Comp. Sci. Vol. 6, N. 2(1993), 151-159.
MR 1239743 |
Zbl 0816.46017
[2] Alsina C., Guijarro P., Tomás M. S.:
A characterization of inner product spaces based on a property of height’s transform. Archiv der Mathematik Vol. 61(1993), 560-566.
MR 1254068
[3] Alsina C., Cruells P., Tomás M. S.:
Isosceles Trapezoids, Norms and Inner Products. Archiv der Mathematik (1999)
MR 1671283 |
Zbl 0928.46010
[5] Suzuki F.:
A Certain Property of an Isosceles Trapezoid and its Application to Chain Circle Problems. Mathematics Magazine Vol. 8, N. 2, pp 136-145 (1995).
MR 1333815 |
Zbl 0877.51017