LIM (1 / ln (1 + x) - 1 / x) x tends to 0

LIM (1 / ln (1 + x) - 1 / x) x tends to 0


lim(1/ln(1+x)-1/x)
=lim[x-ln(1+x)]/xln(1+x)
=lim[1-1/(1-x)]/[ln(1+x)+x/(1+x)]
=limx/[x+(1+x)ln(1+x)]
=lim1/[ln(1+x)+1+1]=1/2



How to use lobita's law to find: LIM (x - > 1 +) (LN x) * ln (x-1)
If I change 1 / ln x into denominator, I can get the limit 0, but why can't I change 1 / ln (x-1) into denominator? In addition, can I use the combination of equivalent infinitesimal to do it


lim(x->1+) (ln x) * ln(x-1)
=lim(x->1+) (ln x) / [1/ln(x-1)]
Obviously, when X - > 1 +, LN X - > 0, and ln (x-1) tends to - ∞, so [1 / ln (x-1)] tends to 0,
By deriving the numerator and denominator at the same time, we get
Original limit
=lim(x->1+) (1/x) / [-1/ (x-1)*ln²(x-1)]
=The denominator of LIM (x - > 1 +) ln & # 178; (x-1) / [1 / (x-1)] tends to infinity, and the derivative is obtained
=lim(x->1+) [2ln(x-1) /(x-1)] / [-1/(x-1)²]
=The denominator of LIM (x - > 1 +) - 2ln (x-1) / [1 / (x-1)] tends to infinity. At the same time, the derivative is obtained
=lim(x->1+) [-2/(x-1)] / [-1/(x-1)²]
=lim(x->1+) 2(x-1)
=0
This is obviously a bit of a hassle
It's a lot easier to do it with an equivalent infinitesimal,
lim(x->1+) (ln x) * ln(x-1)
=lim(x->1+) ln(1+x-1) * ln(x-1)
Obviously, when X - > 1 +, X-1 - > 0 +,
So ln (1 + x-1) and X-1 are equivalent infinitesimals
therefore
Original limit
=lim(x->1+) (x-1) * ln(x-1)
=The denominator of LIM (x - > 1 +) ln (x-1) / [1 / (x-1)] tends to infinity. At the same time, the derivative is obtained
=lim(x->1+) 1/(x-1) / [-1/(x-1)² ]
=lim(x->1+) -(x-1)
=0



LIM (1 / ln (x + 1) - 1 / x) x tends to zero using the law of lobita
LIM (1 / ln (x + 1) - 1 / x) x tends to zero using the law of lobita


Original = [x-ln (x + 1)] / XLN (x + 1)
=[x-ln (x + 1)] / x ^ 2 [ln (x + 1) and X are equivalent infinitesimals when x tends to zero]
=[1-1 / (x + 1)] / 2x [0 / 0 lobita rule]
=x/2x(x+1)
=1/2



Lim → 0 [∫ (upper limit x, lower limit 0) ln (1 + Sint) DT] / 1-cosx


Lim → 0 [∫ (upper limit x, lower limit 0) ln (1 + Sint) DT] / 1-cosx
It can be known from the upper and lower derivatives of the law of Robita (the derivation of the integral with variable upper limit for molecules)
= lim→0[ln(1+sinx)]/sinx
From the equivalent infinitesimal ln (1 + SiNx) = SiNx
= lim→0 (sinx)/sinx
=1



What number is added to the numerator and denominator of 1 / 13 to make it 60%?


1/13
60%=6/10 =18/30
Plus 17



Is half of plural or singular with countable nouns


Let's start with an example
Half of a pencil
Half of them are gone
Conclusion: the singular and plural of "half of" followed by countable nouns can be used



Function f (x) = | (2 ^ x) - 1 |, if AF (b), then the following four formulas hold
A.a


When - ∞



How to form noun phrases in English


A noun phrase is a phrase with a noun as its center. For example, all the college students, the students are the center word, the talk boy sitting in the corner, boy is the center word



As shown in figure I is the heart of △ ABC, the extension line of AI intersects at point D, the circumscribed circle intersects at point E, (1) is be equal to IE? Why? (2) Ie is the proportion of AE and de


① Be = IE & nbsp; & nbsp; & nbsp; & nbsp; prove: connecting Bi. ∵ I is △ ABC core, ∵ 1 = ∵ 2, ∵ 3 = ∵ 5, ∵ 3 = ∵ 4, ∵ 4 = ∵ 5, ∵ BIE = ∵ 2 + ∵ 5,