volume 6, issue 1, article 19, 2005.
Received 12 January, 2005;
accepted 20 January, 2005.
Communicated by:R.P. Agarwal
Abstract Contents
JJ II
J I
Home Page Go Back
Close Quit
Journal of Inequalities in Pure and Applied Mathematics
NOTE ON DRAGOMIR-AGARWAL INEQUALITIES, THE GENERAL EULER TWO-POINT FORMULAE AND CONVEX FUNCTIONS
A. VUKELI ´C
Faculty of Food Technology and Biotechnology Mathematics Department
University of Zagreb Pierottijeva 6, 10000 Zagreb Croatia
EMail:avukelic@pbf.hr
c
2000Victoria University ISSN (electronic): 1443-5756 016-05
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page2of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
Abstract
The general Euler two-point formulae are used with functions possessing var- ious convexity and concavity properties to derive inequalities pertinent to nu- merical integration.
2000 Mathematics Subject Classification:26D15, 26D20, 26D99
Key words: Hadamard inequality, r-convexity, Integral inequalities, General Euler two-point formulae.
Contents
1 Introduction. . . 3 2 The General Euler Two-point Formulae. . . 5
References
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page3of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
1. Introduction
One of the cornerstones of nonlinear analysis is the Hadamard inequality, which states that if [a, b] (a < b) is a real interval and f : [a, b] → R is a convex function, then
(1.1) f
a+b 2
≤ 1 b−a
Z b a
f(t)dt≤ f(a) +f(b)
2 .
Recently, S.S. Dragomir and R.P. Agarwal [3] considered the trapezoid for- mula for numerical integration of functionsfsuch that|f0|qis a convex function for someq≥1. Their approach was based on estimating the difference between the two sides of the right-hand inequality in (1.1). Improvements of their results were obtained in [5]. In particular, the following tool was established.
Supposef :I0 ⊆R→Ris differentiable onI0and such that|f0|qis convex on[a, b]for someq ≥1,wherea, b∈I0(a < b). Then
(1.2)
f(a) +f(b)
2 − 1
b−a Z b
a
f(t)dt
≤ b−a 4
|f0(a)|q+|f0(b)|q 2
1q . Some generalizations to higher-order convexity and applications of these results are given in [1]. Related results for Euler midpoint, Euler-Simpson, Euler two- point, dual Euler-Simpson, Euler-Simpson 3/8and Euler-Maclaurin formulae were considered in [7] and for Euler two-point formulae in [9] (see also [2] and [8]).
In the paper [4] Dah-Yan Hwang procured some new inequalities of this type and he applied the result to obtain a better estimate of the error in the trapezoidal formula.
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page4of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
In this paper we consider some related results using the general Euler two- point formulae. We will use the interval[0,1]because of simplicity and since it involves no loss in generality.
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page5of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
2. The General Euler Two-point Formulae
In the recent paper [6] the following identities, named the general Euler two- point formulae, have been proved. Let f ∈ Cn([0,1],R)for some n ≥ 3 and letx∈[0,1/2]. Ifn= 2r−1, r ≥2, then
(2.1)
Z 1 0
f(t)dt = 1
2[f(x) +f(1−x)]−Tr−1(f)
+ 1
2(2r−1)!
Z 1 0
f(2r−1)(t)F2r−1x (t)dt, while forn = 2r, r≥2we have
(2.2)
Z 1 0
f(t)dt = 1
2[f(x) +f(1−x)]−Tr−1(f)
+ 1
2(2r)!
Z 1 0
f(2r)(t)F2rx(t)dt and
(2.3)
Z 1 0
f(t)dt = 1
2[f(x) +f(1−x)]−Tr(f)
+ 1
2(2r)!
Z 1 0
f(2r)(t)Gx2r(t)dt.
Here we defineT0(f) = 0and for1≤m ≤ bn/2c Tm(f) =
m
X
k=1
B2k(x) (2k)!
f(2k−1)(1)−f(2k−1)(0) ,
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page6of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
Gxn(t) =Bn∗(x−t) +Bn∗(1−x−t) and
Fnx(t) = Bn∗(x−t) +Bn∗(1−x−t)−Bn(x)−Bn(1−x),
where Bk(·), k ≥ 0, is the k-th Bernoulli polynomial and Bk = Bk(0) = Bk(1)(k ≥ 0) the k-th Bernoulli number. By Bk∗(·)(k ≥ 0) we denote the function of period one such thatBk∗(x) =Bk(x)for0≤x≤1.
It was proved in [6] thatFnx(1−t) = (−1)nFnx(t), (−1)r−1F2r−1x (t) ≥ 0, (−1)rF2rx(t)≥0forx∈h
0,12 −2√13
andt∈[0,1/2], and(−1)rF2r−1x (t)≥0, (−1)r−1F2rx(t)≥0forx∈
1 2√
3,12i
andt∈[0,1/2]. Also Z 1
0
F2r−1x (t)
dt= 2 r
B2r 1
2 −x
−B2r(x) ,
Z 1 0
|F2rx(t)|dt= 2|B2r(x)|
and
Z 1 0
|Gx2r(t)|dt ≤4|B2r(x)|.
With integration by parts, we have that the following identities hold:
C1(x) = Z 1
0
F2r−1x y 2
dy (1)
=− Z 1
0
F2r−1x
1− y 2
dy = 2 r
B2r(x)−B2r
1 2−x
,
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page7of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
C2(x) = Z 1
0
yF2r−1x y 2
(2) dy
=− Z 1
0
yF2r−1x 1−y
2
dy
=−2 rB2r
1 2 −x
,
C3(x) = Z 1
0
(1−y)F2r−1x y 2
dy (3)
=− Z 1
0
(1−y)F2r−1x 1− y
2
dy
= 2
rB2r(x),
(4) C4(x) = Z 1
0
F2rx y 2
dy=
Z 1 0
F2rx 1− y
2
dy=−2B2r(x),
C5(x) = Z 1
0
yF2rx y 2
dy (5)
= Z 1
0
yF2rx 1− y
2
dy
= 8
(2r+ 1)(2r+ 2)
B2r+2(x)−B2r+2
1 2−x
−B2r(x),
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page8of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
C6(x) = Z 1
0
(1−y)F2rx y 2
(6) dy
= Z 1
0
(1−y)F2rx 1−y
2
dy
= 8
(2r+ 1)(2r+ 2)
B2r+2 1
2 −x
−B2r+2(x)
−B2r(x),
(7) C7(x) = Z 1
0
Gx2ry 2
dy=
Z 1 0
Gx2r 1− y
2
dy= 0,
C8(x) = Z 1
0
yGx2ry 2
dy (8)
= Z 1
0
yGx2r 1− y
2
dy
=− Z 1
0
(1−y)Gx2ry 2
dy
= Z 1
0
(1−y)Gx2r 1− y
2
dy
= 8
(2r+ 1)(2r+ 2)
B2r+2(x)−B2r+2
1 2−x
,
Theorem 2.1. Suppose f : [0,1] → R is n-times differentiable and x ∈ h
0,12 − 1
2√ 3
∪
1 2√
3,12i .
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page9of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
(a) If f(n)
qis convex for someq≥1,then forn= 2r−1, r ≥2, we have
(2.4)
Z 1 0
f(t)dt− 1
2[f(x) +f(1−x)] +Tr−1(f)
≤ 2 (2r)!
B2r 1
2 −x
−B2r(x)
1−1
q
×
"
r 2C3(x)
·
f(2r−1)(0)
q+
f(2r−1)(1)
q
2 +
r
2C2(x) ·
f(2r−1) 1
2
q1q .
Ifn = 2r, r≥2, then (2.5)
Z 1 0
f(t)dt− 1
2[f(x) +f(1−x)] +Tr−1(f)
≤ |B2r(x)|1−1q (2r)! ·
"
1 2C6(x)
f(2r)(0)
q+
f(2r)(1)
q
2 +
1 2C5(x)
f(2r) 1
2
q1q
and we also have (2.6)
Z 1 0
f(t)dt− 1
2[f(x) +f(1−x)] +Tr(f)
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page10of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
≤ 2|B2r(x)|1−1q (2r)!
1 8C8(x)
f(2r)(0)
q+ 2
f(2r) 1
2
q
+
f(2r)(1)
q1q .
(b) If f(n)
qis concave, then forn = 2r−1, r ≥2, we have
(2.7)
Z 1 0
f(t)dt− 1
2[f(x) +f(1−x)] +Tr−1(f)
≤ 1 (2r)!
r 2C1(x)
·
f(2r−1)
|C2(x)|
2|C1(x)|
+
f(2r−1)
C3(x) + 12C2(x)
|C1(x)|
!
# .
Ifn = 2r, r≥2, then (2.8)
Z 1 0
f(t)dt− 1
2[f(x) +f(1−x)] +Tr−1(f)
≤ |C4(x)|
4(2r)!
f(2r)
|C5(x)|
2|C4(x)|
+
f(2r)
C6(x) + 12C5(x)
|C4(x)|
!
# .
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page11of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
Proof. First, letn = 2r−1for somer≥2. Then by Hölder’s inequality
Z 1 0
f(t)dt− 1
2[f(x) +f(1−x)] +Tr−1(f)
≤ 1
2(2r−1)!
Z 1 0
F2r−1x (t) ·
f(2r−1)(t) dt
≤ 1
2(2r−1)!
Z 1 0
F2r−1x (t) dt
1−1q Z 1 0
F2r−1x (t) ·
f(2r−1)(t)
qdt 1q
= 1
2(2r−1)!
2 r
B2r 1
2−x
−B2r(x)
1−1
q
× Z 1
0
F2r−1x (t) ·
f(2r−1)(t)
qdt 1q
.
Now, by the convexity of|f(2r−1)|qwe have Z 1
0
F2r−1x (t) ·
f(2r−1)(t)
qdt
= Z 12
0
F2r−1x (t) ·
f(2r−1)(t)
qdt+ Z 1
1 2
F2r−1x (t) ·
f(2r−1)(t)
qdt
= 1 2
Z 1 0
F2r−1x y 2
·
f(2r−1)
(1−y)·0 +y· 1 2
q
dy +1
2 Z 1
0
F2r−1x 1− y
2
·
f(2r−1)
(1−y)·1 +y· 1 2
q
dy
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page12of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
≤ 1 2
Z 1 0
(1−y)F2r−1x y 2
dy
·
f(2r−1)(0)
q
+
Z 1 0
yF2r−1x y 2
dy
·
f(2r−1) 1
2
q
+
Z 1 0
(1−y)F2r−1x 1− y
2
dy
·
f(2r−1)(1)
q
+
Z 1 0
yF2r−1x
1− y 2
dy
·
f(2r−1) 1
2
q .
On the other hand, if
f(2r−1)
qis concave, then
Z 1 0
f(t)dt− 1
2[f(x) +f(1−x)] +Tr−1(f)
≤ 1
2(2r−1)!
Z 1 0
F2r−1x (t) ·
f(2r−1)(t) dt
= 1
2(2r−1)!
"
Z 1/2 0
F2r−1x (t) ·
f(2r−1)(t) dt+
Z 1 1/2
F2r−1x (t) ·
f(2r−1)(t) dt
#
= 1
2(2r−1)!
Z 1 0
F2r−1x y 2
·
f(2r−1)
(1−y)·0 +y· 1 2
dy +
Z 1 0
F2r−1x 1− y
2
·
f(2r−1)
(1−y)·1 +y· 1 2
dy
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page13of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
≤ 1
4(2r−1)!
Z 1 0
F2r−1x y 2
dy
×
f(2r−1)
R1
0 F2r−1x y2
((1−y)·0 +y· 12)dy
R1
0 F2r−1x y2 dy
+
Z 1 0
F2r−1x 1− y
2
dy
×
f(2r−1)
R1
0 F2r−1x 1− y2
((1−y)·1 +y· 12)dy
R1
0 F2r−1x 1− y2 dy
,
so the inequality (2.4) and (2.7) are completely proved.
The proofs of the inequalities (2.5), (2.8) and (2.6) are similar.
Remark 1. For (2.7) to be satisfied it is enough to suppose that |f(2r−1)| is a concave function. For if |g|q is concave and [0,1] for some q ≥ 1, then for x, y ∈[0,1]andλ ∈[0,1]
|g(λx+ (1−λ)y)|q ≥λ|g(x)|q+ (1−λ)|g(y)|q≥(λ|g(x)|+ (1−λ)|g(y)|)q, by the power-mean inequality. Therefore|g|is also concave on[0,1].
Remark 2. If in Theorem 2.1 we chose x = 0,1/2,1/3, we get generaliza- tions of the Dragomir-Agarwal inequality for Euler trapezoid (see [4]) , Euler midpoint and Euler two-point Newton-Cotes formulae respectively.
The resultant formulae in Theorem2.1whenr= 2are of special interest, so we isolate it as corollary.
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page14of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
Corollary 2.2. Suppose f : [0,1] → R is 4-times differentiable and x ∈ h
0,12 − 1
2√ 3
∪
1 2√
3,12i . (a) If
f(3)
qis convex for someq ≥1,then
Z 1 0
f(t)dt−1
2[f(x) +f(1−x)] + 1
12[f0(1)−f0(0)]
≤ 1 12
2x3−3
2x2+ 1 16
1−1q
×
"
x4−2x3+x2− 1 30
f(3)(0)
q+
f(3)(1)
q
2 +
−x4+x2 2 − 7
240
f(3) 1
2
q1q
and if f(4)
qis convex for someq≥1,then
Z 1 0
f(t)dt−1
2[f(x) +f(1−x)] + 1
12[f0(1)−f0(0)]
≤ 1 24
x4−2x3+x2− 1 30
1−1q
×
"
2x5
5 −x4 +x3− 3x2 8 + 1
96
f(4)(0)
q+
f(4)(1)
q
2
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page15of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
+
−2x5
5 +x3− 5x2 8 + 11
480
f(4) 1
2
q1q .
(b) If f(3)
is concave, then
Z 1 0
f(t)dt−1
2[f(x) +f(1−x)] + 1
12[f0(1)−f0(0)]
≤ 1 24
2x3− 3
2x2+ 1 16
f(3)
−x4+ x22 − 2407 −4x3+ 3x2− 18
+
f(3)
x4
2 −2x3 +5x42 − 48023 −2x3+ 3x22 − 161
and if f(4)
is concave, then
Z 1 0
f(t)dt−1
2[f(x) +f(1−x)] + 1
12[f0(1)−f0(0)]
≤ 1 48
x4−2x3+x2− 1 30
f(4)
−4x55 + 2x3− 5x42 +24011 −4x4+ 8x3 −4x2+ 152
+
f(4)
2x5
5 −2x4+ 3x3− 11x82 +1607 −2x4+ 4x3−2x2 +151
.
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page16of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
Now, we will give some results of the same type in the case whenr= 1.
Theorem 2.3. Supposef : [0,1]→Ris2-times differentiable.
(a) If|f0|qis convex for someq≥1, then forx∈[0,1/2]we have
Z 1 0
f(t)dt−1
2[f(x) +f(1−x)]
≤ |8x2−4x+ 1|1−1q
4 ·
2x2 −2x+ 2 3
|f0(0)|q+|f0(1)|q 2
+
−2x2+ 2x+1 3
f0 1
2
q1q .
If|f00|q is convex for someq≥1andx∈[0,1/4], then
Z 1 0
f(t)dt−1
2[f(x) +f(1−x)]
≤
−6x2+6x−1
3 +23(1−4x)3/2
1−1q
4
−x2+x− 1 8
|f00(0)|q+|f00(1)|q 2
+
−2x2+ 2x− 5 24
f00 1
2
q1q ,
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page17of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
while forx∈[1/4,1/2]we have
Z 1 0
f(t)dt−1
2[f(x) +f(1−x)]
≤
−6x2+6x−1 3
1−1q
4
−x2+x−1 8
|f00(0)|q+|f00(1)|q 2
+
−2x2+ 2x− 5 24
f00 1
2
q1q .
(b) If|f0|is concave for someq≥1, then forx∈[0,1/2]we have
Z 1 0
f(t)dt−1
2[f(x) +f(1−x)]
≤ 1 8
f0
−x2+x+ 1 6
+
f0
x2−x+5 6
. If|f00|is concave for someq ≥1andx∈[0,1/2], then
Z 1 0
f(t)dt−1
2[f(x) +f(1−x)]
≤ 1 8
−3x2+ 3x− 1 3
"
f00
−2x2+ 2x− 245 −6x2+ 6x− 23
! +
f00
−2x2 + 2x− 1148 −3x2+ 3x− 13
!
# .
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page18of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
Proof. It was proved in [6] that forx∈[0,1/2]
Z 1 0
|F1x(t)|dt = 8x2−4x+ 1
2 ,
forx∈[0,1/4]
Z 1 0
|F2x(t)|dt = −6x2+ 6x−1
3 +2
3(1−4x)3/2, and forx∈[1/4,1/2]
Z 1 0
|F2x(t)|dt= −6x2+ 6x−1
3 .
So, using identities (2.1) and (2.2) with calculation of C1(x), C2(x), C3(x), C4(x), C5(x)andC6(x)similar to that in Theorem2.1we get the inequalities in (a) and (b).
Remark 3. Forx= 0in the above theorem we have the trapezoid formula and for|f00|q a convex function and|f00|a concave function we get the results from [4].
If|f0|qis convex for someq ≥1, then
Z 1 0
f(t)dt−1
2[f(0) +f(1)]
≤ 1 4
"
|f0(0)|q+|f0 12
|q+|f0(1)|q 3
#1q
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page19of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
and if|f0|is concave, then
Z 1 0
f(t)dt−1
2[f(0) +f(1)]
≤ 1 8
f0 1
6
+
f0 5
6
.
Forx= 1/4we get two-point Maclaurin formula and then if|f0|qis convex for someq ≥1, then
Z 1 0
f(t)dt− 1 2
f
1 4
+f
3 4
≤ 1 8
"
7|f0(0)|q+ 34|f0 12
|q+ 7|f0(1)|q 24
#1q
and if|f00|q is convex for someq ≥1, then
Z 1 0
f(t)dt− 1 2
f
1 4
+f
3 4
≤ 1 96
"
3|f00(0)|q+ 16|f00 12
|q+ 3|f00(1)|q 4
#1q .
If|f0|is concave, then
Z 1 0
f(t)dt−1 2
f
1 4
+f
3 4
≤ 1 8
f0 17
48
+
f0 31
48
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page20of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
and if|f00|is concave for someq ≥1, then
Z 1 0
f(t)dt− 1 2
f
1 4
+f
3 4
≤ 11 384
f00 4
11
+
f00 7
11
. For x = 1/3 we get two-point Newton-Cotes formula and then if |f0|q is convex for someq ≥1, then
Z 1 0
f(t)dt− 1 2
f
1 3
+f
2 3
≤ 5 36
"
|f0(0)|q+ 7|f0 12
|q+|f0(1)|q 5
#1q
and if|f00|q is convex for someq ≥1, then
Z 1 0
f(t)dt− 1 2
f
1 3
+f
2 3
≤ 1 36
"
7|f00(0)|q+ 34|f00 12
|q+ 7|f00(1)|q 16
#1q .
If|f0|is concave, then
Z 1 0
f(t)dt−1 2
f
1 3
+f
2 3
≤ 1 8
f0 7
18
+
f0 11
18
and if|f00|is concave for someq ≥1, then
Z 1 0
f(t)dt−1 2
f
1 3
+f
2 3
≤ 1 24
f00 17
48
+
f00 31
48
.
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page21of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
For x = 1/2 we get midpoint formula and then if|f0|q is convex for some q ≥1, then
Z 1 0
f(t)dt−f 1
2
≤ 1 4
"
|f0(0)|q+ 10|f0 12
|q+|f0(1)|q 12
#1q
and if|f00|q is convex for someq ≥1, then
Z 1 0
f(t)dt−f 1
2
≤ 1 24
"
3|f00(0)|q+ 14|f00 12
|q+ 3|f00(1)|q 8
#1q .
If|f0|is concave, then
Z 1 0
f(t)dt−f 1
2
≤ 1 8
f0 5
12
+
f0 7
12
and if|f00|is concave for someq ≥1, then
Z 1 0
f(t)dt−f 1
2
≤ 5 96
f00 7
20
+
f00 13
20
.
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page22of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
References
[1] Lj. DEDI ´C, C.E.M. PEARCEANDJ. PE ˇCARI ´C, Hadamard and Dragomir- Agarwal inequalities, higher-order convexity and the Euler formula, J. Ko- rean Math. Soc., 38 (2001), 1235–1243.
[2] Lj. DEDI ´C, C.E.M. PEARCEAND J. PE ˇCARI ´C, The Euler formulae and convex functions, Math. Inequal. Appl., 3(2) (2000), 211–221.
[3] S.S. DRAGOMIR AND R.P. AGARWAL, Two inequalities for differen- tiable mappings and applications to special means of real numbers and to trapezoidal formula, Appl. Mat. Lett., 11(5) (1998), 91–95.
[4] D.Y. HWANG, Improvements of Euler-trapezodial type inequalities with higher-order convexity and applications, J. of Inequal. in Pure and Appl.
Math., 5(3) (2004), Art. 66. [ONLINE:http://jipam.vu.edu.au/
article.php?sid=412]
[5] C.E.M. PEARCE AND J. PE ˇCARI ´C, Inequalities for differentiable map- pings and applications to special means and quadrature formulas, Appl.
Math. Lett., 13 (2000), 51–55.
[6] J. PE ˇCARI ´C, I. PERI ´C AND A. VUKELI ´C, On general Euler two-point formulae, to appear in ANZIAM J.
[7] J. PE ˇCARI ´C AND A. VUKELI ´C, Hadamard and Dragomir-Agarwal in- equalities, the Euler formulae and convex functions, Functional Equations, Inequalities and Applications, Th.M. Rassias (ed.)., Dordrecht, Kluwer Academic Publishers, 2003.
Note on Dragomir-Agarwal Inequalities, the General Euler
Two-Point Formulae and Convex Functions
A. Vukeli´c
Title Page Contents
JJ II
J I
Go Back Close
Quit Page23of23
J. Ineq. Pure and Appl. Math. 6(1) Art. 19, 2005
http://jipam.vu.edu.au
[8] J. PE ˇCARI ´CANDA. VUKELI ´C, On generalizations of Dragomir-Agarwal inequality via some Euler-type identities, Bulletin de la Société des Mathé- maticiens de R. Macédoine, 26 (LII) (2002), 17–42.
[9] J. PE ˇCARI ´C AND A. VUKELI ´C, Hadamard and Dragomir-Agrawal in- equalities, the general Euler two-point formulae and convex function, to appear in Rad HAZU, Matematiˇcke Znanosti.