ABSTRACT
Together with the convex set introduced in Chapter 2, convex function is required
to define a convex optimization problem to be introduced in Chapter 4. This
chapter introduces the basics of convex functions, and quasiconvex functions
including definitions, properties, representations and convexity preserving oper-
ations, and various conditions for proving or disproving if a function is convex
or quasiconvex. These concepts are also extended to K-convex functions defined
on a proper cone K. Many examples are provided to illustrate how to prove the
convexity and quasiconvexity of functions.
