Thread: Analysis question no.2

if we know that f : [a,b] ----> reals is continuous. How can we prove that the image f([a,b]) is a closed interval say [m,M] for some m,M in reals?

A continuous function maps a compact set to a compact set.

Originally Posted by maximus101

if we know that f : [a,b] ----> reals is continuous. How can we prove that the image f([a,b]) is a closed interval say [m,M] for some m,M in reals?

Or, perhaps a little simpler answer than HallsofIvy's, put and now use the

intermediate value theorem for continuous functions...

Tonio