If x>0, then log(1+x)<x.
My attempt at the proof thus far...
Let f(x)=x−log(1+x), then f′(x)=1−11+x for some μ∈(0,x) (since x>0)
MVT give us f(x)=f(a)+f′(μ)(x−a)
So plug in our values we get:
x−log(1+x)=0+(1−11+μ)(x−0)
which we can reduce to
log(1+x)=x1+μ
Now For x≤1, then 0<μ<1
S0 0<11+μ<1, thus log(1+x)<x
If x>1, then....
So I can see clearly that if x>1 is plugged into x1+μ
then $\log(1+x)
I would appreciate tips hints or proof completions.
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