How Can I Prove (1+x/n^n < e^x)?

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SUMMARY

The inequality (1 + x/n)^n < e^x can be proven using the binomial theorem and power series expansion for e^x. By applying logarithms to both sides, the left-hand side can be expanded, revealing that for x > 0, the inequality holds clearly. For x < 0, a more nuanced approach is required, involving the manipulation of terms in pairs to establish the inequality. This method provides a definitive proof of the stated inequality.

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wowolala
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the quesion is below, show that
show that ( 1+ \frac{x}{n} ) ^n < e^x

at the first, i take log on both sides,.. but i couldn't go further.

can someboday help me?

thx
 
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What do you get when you apply log to both sides?
 
wowolala said:
the quesion is below, show that
show that ( 1+ \frac{x}{n} ) ^n < e^x

at the first, i take log on both sides,.. but i couldn't go further.

can someboday help me?

thx
Expand the lhs by the binomial theorem and take the power series for e^x. The solution becomes obvious for x>0. For x<0, it is a little trickier - work with terms 2 at a time.
 
Last edited:
thx so much
 

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