maths

Posted by s on Jun 19, 2012; 12:10pm
URL: http://discussion-forum.276.s1.nabble.com/maths-tp7578219.html

the function f(x)=max{x,1} is

a. not quasi convex
b. quasi convex but not convex
c. convex
d. concave

ans is convex..why is it not quasi convex?