In this paper, we mainly discuss the asymptotic property of mediant for order Lagrange’s mean value theorem, and obtain the general results for this problem:
Differential mean value theorem is an important theorem in advanced mathematics, over the years, there are many papers concerning the intermediate point of differential mean value theorem, and many related results have been obtained, such as the Lagrange mean value theorem in the literature, the authors studied the second-order, third-order and fourth-order gradual properties of middle value theorem in some cases, For example, for the fourth order mean value theorem, the authors got the following conclusions:
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In the literature 7, the authors studied the five order situation, and then further generalized the result of the above. Inspired from some research in the literature, and the results given in the similarity, we should naturally consider this question for any order of mean value theorem. In this article, we used the combination mathematics knowledge, we further study the asymptotic property of mediant for any order’s mean value theorem, and obtain the general results for this problem, as a result, we generalize the corresponding results of other authors.
In order to prove our main results, we first need the following two lemms.
Lemma 2.1. ( 4) Let be continuous on
and has a derivative of order
at the interior points of the interval
, then there exists a point
such that
![]() | (2.1) |
Lemma 2.2. ( 2) For any , we have:
![]() |
Corollary 2.3. For any , we have:
![]() | (2.2) |
![]() | (2.3) |
Proof. We can obtain these two inequalities by simple computation, here we omit the details.
In this section, we will prove our main results in this paper.
Theorem 3.1. Let be continuous on interval
and has a derivative of order
at the interior points of the interval
. If
has a derivative of order
at the point
and
, then for any
, there exists a point
satisfies (2.1) and
![]() |
Proof. For any since
is continuous on
and has a derivative of order
at the interior points of the interval
, then from (1.1):
![]() | (3.1) |
Now, construct such that:
![]() | (3.2) |
where Using (3.1), we can obtain
![]() |
Now, let , we have
![]() | (3.3) |
On the other hand, applying Hopital’s rule to (3.2):
![]() |
Now, applying Hopital’s rule to for n times:
![]() | (3.4) |
By using Corolly 2.3 and (3.4), we can botian the following
![]() | (3.5) |
Using Corollary 2.3 again, then from (3.5),
![]() | (3.6) |
It follows from (3.6) and (3.6) that
![]() |
This completes the proof.
Theorem 3.2. Let be continuous on interval
and has a derivative of order
at the interior points of the interval
. If
is continuous at the point
and
then for any
there exists a point
satisfies (2.1) and
![]() |
Proof. Construct such that
![]() | (3.7) |
Using (3.1), we can obtain
![]() | (3.8) |
Applying Taylor's formula to we have
![]() | (3.9) |
Now, applying (3.9) to (3.8),
![]() |
Let , we get
![]() | (3.10) |
On the other hand, applying Hopital’s rule to (3.7) for n times:
![]() | (3.11) |
It follows from (3.5) and (3.6) that
![]() |
This completes the proof.
Remark 3.3. If we put in our Theorem 3.1 and Theorem 3.2, then we can some related results in the literature, thus, we obtain the general results for this problem.
The author is grateful to the referee and editors for their helpful comments and suggestions.
[1] | G. Xu, Asymptotic property of mediant for Lagrange's and Cauchy's theorem of second Order, Journal of Beijing Institute of Clothing, 1990, 201-205. | ||
In article | View Article | ||
[2] | B. Chen, On Several new methods to proof combinatorial identities, Journal of Ningxia University (Natural Science Edition), 2004, 231-233. | ||
In article | PubMed | ||
[3] | Y. Ding, A further research on intermediate point in the second mean value theorem for integrals, Journal of Hefei Teachers College; 2009, 304-306. | ||
In article | View Article | ||
[4] | X. Zhang and W Wang, A class of differential intermediate value theorem and its asymptotic behavior of mediant, Journal of Beijing Institute of Clothing, 2001, 181-185. | ||
In article | |||
[5] | J. Du, The forms of higher order of Cauchy’s and Lagrange’s mean value theorem, Journal of Huaibei Coal Industry Teachers College, 2001, 211-215. | ||
In article | |||
[6] | W. Rudin, Principles of mathematical analysis, New York: McGraw-Hill.1976. | ||
In article | View Article | ||
[7] | T. M Apostol, Mathematical analysis, Addison-Wesley Pub. Co.1974. | ||
In article | View Article | ||
[8] | W, Wang, Asymptotic Behaviour of mediant for integral F form Cauchy's mean value theorem, Journal of Beijing Institute of Clothing, 2005, 25-27. | ||
In article | View Article | ||
[9] | Q. Zheng, The asymptotic property of the intermediate value of the first mean value theorem for the integrals and the quadrature formula, College Mathematies, 2004, 6-9. | ||
In article | PubMed | ||
Published with license by Science and Education Publishing, Copyright © 2017 Jianbing Cao
This work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit
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[1] | G. Xu, Asymptotic property of mediant for Lagrange's and Cauchy's theorem of second Order, Journal of Beijing Institute of Clothing, 1990, 201-205. | ||
In article | View Article | ||
[2] | B. Chen, On Several new methods to proof combinatorial identities, Journal of Ningxia University (Natural Science Edition), 2004, 231-233. | ||
In article | PubMed | ||
[3] | Y. Ding, A further research on intermediate point in the second mean value theorem for integrals, Journal of Hefei Teachers College; 2009, 304-306. | ||
In article | View Article | ||
[4] | X. Zhang and W Wang, A class of differential intermediate value theorem and its asymptotic behavior of mediant, Journal of Beijing Institute of Clothing, 2001, 181-185. | ||
In article | |||
[5] | J. Du, The forms of higher order of Cauchy’s and Lagrange’s mean value theorem, Journal of Huaibei Coal Industry Teachers College, 2001, 211-215. | ||
In article | |||
[6] | W. Rudin, Principles of mathematical analysis, New York: McGraw-Hill.1976. | ||
In article | View Article | ||
[7] | T. M Apostol, Mathematical analysis, Addison-Wesley Pub. Co.1974. | ||
In article | View Article | ||
[8] | W, Wang, Asymptotic Behaviour of mediant for integral F form Cauchy's mean value theorem, Journal of Beijing Institute of Clothing, 2005, 25-27. | ||
In article | View Article | ||
[9] | Q. Zheng, The asymptotic property of the intermediate value of the first mean value theorem for the integrals and the quadrature formula, College Mathematies, 2004, 6-9. | ||
In article | PubMed | ||