2003f'(x)+2004f(x) >= 2004
hence f'(x) >= (2004/2003)*(1-f(x))
now case 1) 1-f(x) > 0 or f(x) <1
f'(x)/ [1-f(x)} >= (2004/2003)
integrate on both sides:
you will get :
-ln[1-f(x)] > = (2004/2003)x
or ln[1-f(x)] < = (2004/2003)x
or f(x) > =1+ e^ (2004/2003)x
hence f(x) >1 which is not possible as we take f(x) < 1
so no such f(x) possible in this case
case (2) f(x) > 1 or [1 - f(x)] < 0
f'(x)/ [1-f(x)] <= (2004/2003)
integrate on both sides:
you will get :
-ln[1-f(x)] < = (2004/2003)x
or ln[1-f(x)] > = (2004/2003)x
or f(x) < =1+ e^ (2004/2003)x
hence f(x) <1 which is not possible as we take f(x) > 1
so no such f(x) possible in this case
so only function possible is : f(x) =1