Steven G. Krantz 
Convex Analysis [PDF ebook] 

The book showcases convexity in the context of mathematical analysis. It introduces analytic tools for studying convexity and provides analytical applications of the concept. The book includes a general background in classical geometric theory which allows readers to obtain a glimpse of how modern mathematics is developed and how geometric ideas may be studied analytically. Featuring a user-friendly approach, the book contains copious examples and plenty of figures to illustrate the ideas presented. It also includes a thorough glossary to help readers with unfamiliar terms.