i tried to solve this question..

[transgalactic]

the question:

there is a function f(x) which is continues in the borders [a,b]
and derivitable in the borders (a,b), b>a>0
alpha differs 0
prove the there is b>c>a

in that formula:
http://img392.imageshack.us/my.php?image=81208753je3.gif

my trial:

http://img149.imageshack.us/img149/4647/img9136sg3.gif

i dont know what the purpose of this question
what doi need to do next??