Hi all..

i want to ask you about this question in real analysis..

"suppose that f continuous on [a,b] , that f(x) >= 0 (more or equal 0 ) for all x in [a,b] and that http://up.v1va.com/files/xfhdxtawmu5q9lg5y8mf.jpg=0

prove that f(x)=0 for all x in [a,b] "