Hostname: page-component-8448b6f56d-sxzjt Total loading time: 0 Render date: 2024-04-18T04:08:19.099Z Has data issue: false hasContentIssue false

Inequalities for Positive Series

Published online by Cambridge University Press:  31 October 2008

C. E. Walsh
Affiliation:
34 Chelmsford Road, Ranelagh, Dublin
Rights & Permissions [Opens in a new window]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Let f(x) ≡ (1 – x)b + b ab-1 x

ø (x) ≡ xc – c Βc-1 x

where b ≧ 1, c ≧ 1, 0 ≦ α ≦ 1, 0 ≦ β ≦ 1, and x is assumed to lie in the range (0, 1). By differentiation, or otherwise, it is easily shewn that f(x) and ø (x) have minima when x = 1 – α and when x = β, respectively. Hence

(1 – x)b + ab-1 x ≧ b ab-1 + (1 – b) ab

xc βc-1 x ≧ (1 – c)βc.

Type
Research Article
Copyright
Copyright © Edinburgh Mathematical Society 1940

References

1 Copson, , Journal London Math. Society 32 (1927), 912CrossRefGoogle Scholar; 3(1928), 49–51. Elliott, Ibid., 1 (1926), 93–96; 4 (1929). 21–23.