Monday, 8 October 2018

real analysis - prove log(1+x)0

Prove log(1+x)<x for x>0



my attempt:




I show ex>1+x for x>0
since



ex=1+x+n(n1)2x2n2+...



so if x>0 then all terms are positive



so ex>1+x for x>0




now given ex>1+x for x>0, can I take log on both sides and show



log(1+x)<x for x>0



or do I have to prove firstly that exp(x)=ex for x>0 then I can take log..

No comments:

Post a Comment

real analysis - How to find limhrightarrow0fracsin(ha)h

How to find lim without lhopital rule? I know when I use lhopital I easy get $$ \lim_{h\rightarrow 0}...