#Two functions have the same order

13 messages · Page 1 of 1 (latest)

limpid pawnBOT
copper dust
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Yep, that's the idea
To simplify logarithms, factor polynomials by their dominant term (the x^n with the biggest n) and use log(ab) = log(a)+log(b)

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For the factorial, you can use that same property of log (I don't know your definition of x! But maybe you can stick to n! with n integer)

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And for polynomials without log, you can just look at the dominant term

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That's the correct intuition. What makes you think that ?

copper dust
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Yep ! So, between C and D

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For C, on one hand we have xlog(x) which is equal to log(x^x). And on the other hand, log(x²+1) which is roughly the same as log(x²) when x is big

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(the exercise says x>1, but intuitively it actually asks for the behavior when x goes to +∞ )

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What you can say is log(x²) = 2log(x) yes

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(which is of order log(x) )

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Nope, because log(x²)=2log(x) is of the same order as log(x)

copper dust
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You're welcome 😌

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.solved