Journal of Inequalities in Pure and Applied Mathematics ESTIMATION FOR BOUNDED SOLUTIONS OF INTEGRAL INEQUALITIES INVOLVING INFINITE INTEGRATION LIMITS volume 7, issue 5, article 189, 2006. MAN-CHUN TAN AND EN-HAO YANG Department of Mathematics Jinan University Guangzhou 510632 People’s Republic of China Received 02 April, 2006; accepted 31 July, 2006. Communicated by: W.S. Cheung EMail: tanmc@jnu.edu.cn Abstract Contents JJ J II I Home Page Go Back Close c 2000 Victoria University ISSN (electronic): 1443-5756 101-06 Quit Abstract Some integral inequalities with infinite integration limits are established as generalizations of a known result due to B.G. Pachpatte. 2000 Mathematics Subject Classification: 26D10, 45J05. Key words: Nonlinear integral inequality, Infinite integration limit, Explicit bound on solutions. Project supported by the National Natural Science Foundation of P.R. China (No.50578064), and the Natural Science Foundation of Guangdong Province of P.R. China (No.06025219). Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits Man-chun Tan and En-hao Yang Contents 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Linear Generalizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3 Nonlinear Extensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 4 Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 References Title Page Contents JJ J II I Go Back Close Quit Page 2 of 20 J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au 1. Introduction As well known, various differential and integral inequalities have played a dominant role in the development of the theories of differential, functional-differential as well as integral equations. The most powerful integral inequalities applied frequently in the literature are the famous Gronwall-Bellman inequality [1] and its first nonlinear generalization due to Bihari (cf., [2]). A large number of generalizations and their applications of the Gronwall-Bellman inequality have been obtained by many authors (cf., [4] – [7], [3], [5]). Pachpatte [6, p. 28] proved the following interesting variant of the Gronwall-Bellman inequality which contains an infinite integration limit: Theorem A. LetRf be a nonnegative continuous function defined for t ∈ R+ = ∞ [0, ∞) such that 0 f (s)ds < ∞ and c(t) > 0 be a continuous and decreasing function defined for t ∈ R+ . If u(t) ≥ 0 is a bounded continuous function defined for t ∈ R+ and satisfies Z ∞ u(t) ≤ c(t) + f (s)u(s)ds, t ∈R+ , t then Z u(t) ≤ c(t) exp ∞ f (s)ds , t ∈ R+ . t We note that, the condition above on c(t) can be relaxed to only require that, it is nonnegative, continuous and nonincreasing on R+ . The importance of the last result was indicated in [6] by the fact that, it can be used to derive the Rodrigues’ inequality [8] that played a crucial role in the study of many perturbed linear delay differential equations. Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits Man-chun Tan and En-hao Yang Title Page Contents JJ J II I Go Back Close Quit Page 3 of 20 J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au The aim of the present paper is to establish some new linear and nonlinear generalizations of Theorem A. In the sequel, we denote by C(S, M ) the class of continuous functions defined on set S with range contained in set M . Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits Man-chun Tan and En-hao Yang Title Page Contents JJ J II I Go Back Close Quit Page 4 of 20 J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au 2. Linear Generalizations Firstly we show that an inversed version of Theorem A is valid: R∞ Theorem 2.1. Let f ∈ C(R+ , R+ ) satisfy the condition 0 f (s)ds < ∞ and m ∈ C(R+ , (0, ∞)) be nondecreasing. If x ∈ C(R+ , R+ ) is bounded and satisfies the inequality Z ∞ (2.1) x(t) ≥ m(t) + f (s)x(s)ds, t ∈R+ , Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits t then Z (2.2) ∞ x(t) ≥ m(t) exp f (s)ds, t ∈R+ . Man-chun Tan and En-hao Yang t Proof. From (2.1) we derive (2.3) Title Page x(t) 1 >1+ m(t) − ε m(t) − ε Z ∞ ≥1+ f (s) t Z Contents ∞ f (s)x(s)ds t x(s) ds, m(s) − ε t ∈R+ , x(t) > [m(t) − ε]V (t), II I Go Back where ε > 0 is an arbitrary number satisfying m(0) − ε > 0. Define a positive and nonincreasing function V ∈ C(R+ , R+ ) by the right member of (2.3). Then we have V (∞) = 1 and (2.4) JJ J t ∈ R+ . Close Quit Page 5 of 20 J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au By differentiation we obtain dV (t) x(t) = −f (t) < −f (t)V (t), dt m(t) − ε Rewrite the last relation in the form dV (t) < −f (t), V (t)dt t ∈ R+ . t ∈ R+ , and integrating its both sides from t to ∞,then we have Z ∞ ln V (∞) − ln V (t) < − f (s)ds, t ∈R+ , t i.e., Man-chun Tan and En-hao Yang ∞ Z V (t) > exp Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits f (s)ds , t ∈R+ . t Substituting the last relation into (2.4), and letting ε → 0, the desired inequality (2.2) follows. From Theorem A and Theorem 2.1, we obtain the following R∞ Corollary 2.2. Let f ∈ C(R+ , R+ ) satisfy 0 f (s)ds < ∞. Let c ≥ 0 be a constant. Then the linear integral equation Z ∞ (2.5) x(t) = c + f (s)x(s)ds, t ∈R+ , Title Page Contents JJ J II I Go Back Close t has an unique bounded continuous solution represented by Z ∞ (2.6) x(t) = c exp f (s)ds, t ∈R+ . Quit Page 6 of 20 t J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au Proof. If c > 0, by letting c(t) ≡ c and A and R ∞m(t) ≡ c respectively in Theorem R∞ Theorem 2.1, we have x(t) ≤ c exp t f (s)ds and x(t) ≥ c exp t f (s)ds. Hence (2.6) is the unique bounded continuous solution of the equation (2.5). By the continuous dependence on c of x(t) given by (2.6), the conclusion holds also when c = 0. The next result is a new generalization of Pachpatte’s inequality in the case when an iterated integral functional is involved. Theorem 2.3. Let n ∈ C(R+ , R R +∞)be nonincreasing. Let f, h ∈ C(R+ , R+ ),g ∈ 0 C(R+ , R+ ) with g (t) ≥ 0 and 0 [f (s) + g(s)h(s)]ds < ∞. If x ∈ C(R+ , R+ ) is bounded and satisfies the inequality Z ∞ Z ∞ (2.7) x(t) ≤ n(t) + f (s) x(s) + g(s) h(k)x(k)dk ds, t ∈R+ , t Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits Man-chun Tan and En-hao Yang s then Title Page Z ∞ Z ∞ (2.8) x(t) ≤ n(t) 1+ f (s) exp [f (k)+g(k)h(k)]dk ds , t ∈ R+ . Contents t s Proof. From (2.7) we have (2.9) x(t) n(t) + ε Z ∞ Z ∞ 1 < 1+ f (s) x(s) + g(s) h(k)x(k)dk ds n(t) + ε t s Z ∞ Z ∞ x(s) x(k) + g(s) h(k) dk ds, t ∈R+ , < 1+ f (s) n(s) + ε n(k) + ε t s JJ J II I Go Back Close Quit Page 7 of 20 J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au where ε > 0 is an arbitrary positive number. Define a function V ∈ C(R+ , R+ ) by the right member of inequality (2.9). Then V (t) is positive and nonincreasing with V (∞) = 1, and by (2.9) we have (2.10) x(t) < [n(t) + ε] V (t), t ∈ R+ . By differentiation we obtain Z ∞ x(t) x(k) dV (t) = −f (t) + g(t) h(k) dk dt n(t) + ε n(k) + ε t Z ∞ ≥ −f (t) V (t) + g(t) h(k)V (k)dk , t ∈ R+ . t Now we define Man-chun Tan and En-hao Yang Z W (t) = V (t) + g(t) ∞ h(k)V (k)dk. t Title Page Then W (t) ∈ C(R+ , R+ ) is positive, W (∞) = V (∞) = 1, and we have (2.11) W (t) ≥ V (t), t ∈ R+ , and dV (t) ≥ −f (t) W (t), t ∈ R+ . dt By differentiation we derive Z ∞ dV (t) dW (t) 0 (2.13) = + g (t) h(k)V (k)dk − g(t)h(t)V (t) dt dt t ≥ − [f (t) + g(t)h(t)] W (t), t ∈ R+ , (2.12) Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits Contents JJ J II I Go Back Close Quit Page 8 of 20 J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au here (2.11) and (2.12) are used. Rewrite the last relation in the form dW (t) ≥ − [f (t) + g(t)h(t)], t ∈ R+ , W (t)dt and then integrating both sides from t to ∞, we obtain Z ∞ ln W (∞) − ln W (t) ≥ − [f (k) + g(k)h(k)]dk, t or ∞ Z W (t) ≤ exp t ∈ R+ . [f (k) + g(k)h(k)]dk , t Substituting the last inequality into (2.12) and then integrating both sides from t to ∞, we have Z ∞ Z ∞ V (∞) − V (t) ≥ − f (s) exp [f (k) + g(k)h(k)]dk ds, t s V (t) ≤ 1 + ∞ Z f (s) exp t ∞ Contents t ∈R+ . [f (k) + g(k)h(k)]dk ds, s From inequality (2.10) we obtain Z Z ∞ x(t) < [n(t)+ε] 1 + f (s) exp t ∞ Man-chun Tan and En-hao Yang Title Page i.e., Z Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits [f (k) + g(k)h(k)]dk ds , t ∈ R+ . s Hence, by letting ε → 0 the desired inequality (2.8) follows from the last relation directly. Note that, if g(t) ≡ 0 or h(t) ≡ 0, then from Theorem 2.3 we derive Theorem A. JJ J II I Go Back Close Quit Page 9 of 20 J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au 3. Nonlinear Extensions R∞ Theorem 3.1. Let f ∈ C(R+ , R+ ) satisfy the condition 0 f (s)ds < ∞ and c is a nonnegative number. Let ϕ, ψ ∈ C(R+ , R+ ) be strictly increasing and ϕ−1 denote the inverse of ϕ. If x ∈ C(R+ , R+ ) is bounded and satisfies the inequality Z ∞ (3.1) ϕ[x(t)] ≤ c + f (s)ψ[x(s)]ds, t ∈R+ , t Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits then for t ∈ (T, ∞) we have x(t) ≤ ϕ (3.2) −1 ◦ G−1 c Z ∞ f (s)ds , Man-chun Tan and En-hao Yang t where G−1 c is the inverse of Gc and Z z ds , (3.3) Gc (z) := −1 c ψ ◦ ϕ (s) Title Page Contents z ≥ c, and T > 0 is the smallest number satisfying the condition Z ∞ (3.4) f (s)ds ∈ Dom(G−1 ), as long as t ∈ (T, ∞). t Proof. Without loss of generality we may assume c > 0. Otherwise we may replace it by an arbitrary positive number ε and then let ε → 0 in (3.1) and (3.2) to complete the proof. JJ J II I Go Back Close Quit Page 10 of 20 J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au Define a nonincreasing and differentiable function H ∈ C(R+ , [c, ∞)) by the right member of (3.1), then we have (3.5) x(t) ≤ ϕ−1 [H(t)], t ∈ R+ , and H(∞) = c holds. By differentiation we obtain dH(t) = −f (t)ψ[x(t)] ≥ −f (t)ψ ◦ ϕ−1 [H(t)], dt where we used inequality (3.5). Rewrite this relation as dH(t) ≥ −f (t), ψ ◦ ϕ−1 [H(t)]dt t ∈ R+ , t ∈ R+ . Integrating both sides from t to ∞, we derive Z ∞ Gc (H(∞)) − Gc (H(t)) ≥ − f (s)ds, Man-chun Tan and En-hao Yang t ∈R+ , t i.e., Z Gc (H(t)) ≤ Gc (c) + Title Page Contents ∞ f (s)ds, Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits t ∈R+ , t where the function Gc is defined by (3.3). Since Gc (c) = 0, in view of the choice of T in (3.4), the last relation implies Z ∞ −1 H(t) ≤ Gc f (s)ds , t ∈ (T, ∞). JJ J II I Go Back Close Quit t Finally, substituting the last inequality into (3.5), the desired inequality (3.2) follows immediately. Page 11 of 20 J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au Remark 1. In the case when c = 0 and ϕ(0) = ψ(0) = 0 hold, to ensure the correct definition of the function G(z), an additional condition is needed, namely, Z 1 ds lim = M < ∞. δ→0 δ ψ ◦ ϕ−1 (s) Theorem 3.2. Let p, q be positive numbers and c ∈ C(R+ , RR+ ) be positive and ∞ nonincreasing. Let f ∈ C(R+ , R+ ) satisfy the condition 0 f (s)ds < ∞. If x ∈ C(R+ , R+ ) is bounded and satisfies the inequality Z ∞ p (3.6) [x(t)] ≤ c(t) + f (s)[x(s)]q ds, t ∈R+ , t Man-chun Tan and En-hao Yang the following conclusions are true: (I) If p > q, Title Page 1 p−q Z p−q ∞ (q−p)/p 1/p c(s) f (s)ds , (3.7) x(t) ≤ c (t) 1 + q t t ∈ R+ ; (II) If p = q, (3.8) Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits x(t) ≤ c 1/p Z ∞ 1 (t) exp f (s)ds , t ∈ R+ ; p t (III) If p < q, (3.9) x(t) ≤ c Contents JJ J II I Go Back Close Quit 1/p 1 p−q Z p−q ∞ (q−p)/p c(s) f (s)ds , t ∈ (T, ∞), (t) 1+ p t Page 12 of 20 J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au where T is the smallest non-negative number that satisfies Z ∞ p c(s)(q−p)/p f (s)ds ≤ . q−p T Proof. (I) If p > q holds, from inequality (3.6) we obtain Z ∞ p y (t) ≤ 1 + c(s)(q−p)/p f (s)y q (s)ds, t ∈ R+ , t x(t) where y(t) := c1/p . The last integral inequality is a special case of (3.1) when (t) p ϕ(ξ) = ξ , ψ(η) = η q . By (3.3) we derive Z z p G1 (z) = s−q/p ds = (z (p−q)/p − 1), p − q 1 and hence, Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits Man-chun Tan and En-hao Yang Title Page p p−q p−q −1 G1 (v) = v+1 . p Contents JJ J Since G−1 1 (v) ⊃ [0, ∞) holds, from (3.2) we derive that Z ∞ x(t) −1 −1 (q−p)/p ≤ ϕ ◦ G1 c(s) f (s)ds c1/p (t) t Z ∞ p1 −1 (q−p)/p = G1 c(s) f (s)ds Go Back Close Quit t 1 p−q Z p−q ∞ (q−p)/p = 1+ c(s) f (s)ds , p t II I t ∈ R+ . Page 13 of 20 J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au The desired inequality (3.7) follows from the last relation directly. h ip x(t) (II) If p = q holds, letting z(t) = c1/p ,from (3.6) we derive (t) ∞ Z (3.10) z(t) ≤ 1 + f (s)z(s)ds, t ∈ R+ . t Define a positive, nonincreasing and differentiable function V (t) by the right member of (3.10), then z(t) ≤ V (t) and V (∞) = 1 hold. Since c(t), f (t), z(t) are nonnegative, by differentiation we obtain from (3.9) V 0 (t) = −f (t)z(t) ≥ −f (t)V (t), t ∈ R+ , Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits Man-chun Tan and En-hao Yang i.e., V 0 (t) ≥ −f (t), V (t) t ∈ R+ . Title Page Integrating both sides of the last relation from t to ∞, then we have Z ∞ ln V (∞) − ln V (t) ≥ − f (s)ds, t ∈R+ , t or Z ln V (t) ≤ ln V (∞) + Contents JJ J II I Go Back ∞ f (s)ds, t ∈R+ . Close t Hence we obtain p Z ∞ x(t) = z(t) ≤ V (t) ≤ exp f (s)ds , c1/p (t) t Quit Page 14 of 20 t ∈ R+ . J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au This relation implies the desired inequality (3.8) immediately. (III) If p < q holds, similar to the process of (I), we can get p G1 (z) = (z (p−q)/p − 1), p−q Since G−1 1 (v) ∞ Z c(s)(q−p)/p f (s)ds = T p p−q p−q = v+1 . p p , q−p we can derive (3.11) p−q 1+ p Z ∞ c(s)(q−p)/p f (s)ds > 0, for t ∈ (T, ∞). Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits Man-chun Tan and En-hao Yang t R∞ (q−p)/p Inequality (3.11) ensures that G−1 c(s) f (s)ds exists for t ∈ 1 t (T, ∞). Then we get the desired inequality (3.9). Note that, Theorem A is a special case of Theorem 3.2 (II), when p = q = 1. Some similar integral inequalities without infinite integration limits had been established by Yang [8, 9]. Corollary 3.3. Let p,Rq be positive numbers with p ≤ q. Let f ∈ C(R+ , R+ ) ∞ satisfy the condition 0 f (s)ds < ∞. Then x(t) ≡ 0 (t ∈ R+ ) is the unique bounded continuous and nonnegative solution of inequality Z ∞ p (3.12) [x(t)] ≤ f (s)[x(s)]q ds, t ∈R+ . Title Page Contents JJ J II I Go Back Close Quit Page 15 of 20 t J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au Proof. Let x ∈ C(R+ , R+ ) be any bounded function satisfying (3.12). We obtain Z ∞ p (3.13) [x(t)] ≤ ε + f (s)[x(s)]q ds, t ∈R+ , t where ε is an arbitrary positive number. When p < q and ε is small enough, the inequality Z ∞ p ε(q−p)/p f (s)ds < q−p t holds for all t ∈ R+ . A suitable application of Theorem 3.2 to (3.13) yields that, for t ∈ R+ x(t) ≤ h 1/p 1+ ε p−q p R∞ t ε (q−p)/p i h ε1/p exp 1 R ∞ f (s)ds , p t f (s)ds 1 i p−q , p < q; Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits Man-chun Tan and En-hao Yang Title Page Contents p = q. Finally, letting ε → 0, from the last relation we obtain x(t) ≡ 0, t ∈ R+ . If the condition p ≤ q is replaced by p > q, the result x(t) ≡ 0R cannot be ∞ derived directly from Theorem 3.2. In fact, if p > q and M (t) := t f (s)ds, then 1 1 p−q p−q Z ∞ p − q p − q lim ε1/p 1 + ε(q−p)/p f (s)ds = M (t) . ε→0 p p t JJ J II I Go Back Close Quit Page 16 of 20 J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au 4. Examples Example 4.1. Let x ∈ C(R+ , R+ ) be bounded and satisfy the integral inequality Z ∞ s e−3s x(s)ds, x(t) ≥ 1 + t ∈R+ . t Then by Theorem 2.1, we have Z ∞ 3t + 1 −3t −3s e , x(t) ≥ exp se ds = exp 9 t t ∈R+ . Example 4.2. Let x ∈ C(R+ , R+ ) be a bounded function satisfying the inequality Z ∞ Z ∞ Z ∞ −s −s x(t) ≤ 1 + e x(s)ds + e e−k x(k)dk ds, t ∈R+ . t t Man-chun Tan and En-hao Yang Title Page s Then by Theorem 2.3 ,we easily establish Z Z ∞ −s x(t) ≤ 1 + e exp t Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits Contents ∞ 2e−k dk ds JJ J II I s 1 = 1 + exp 2e−t , 2 t ∈ R+ . Example 4.3. Let x ∈ C(R+ , R+ ) be a bounded function satisfying the inequality Z ∞ e−3s x(s)ds, x1/2 (t) ≤ 1 + t Go Back Close Quit Page 17 of 20 t ∈R+ . J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au Since dom G−1 1 Z ∞ −3s e t ds = dom 3 3 − e−3t ⊃ R+ holds, referring to the proof of Theorem 3.2, we obtain 2 3 , t ∈ R+ . x(t) ≤ 3 − e−3t Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits Man-chun Tan and En-hao Yang Title Page Contents JJ J II I Go Back Close Quit Page 18 of 20 J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au References [1] R. BELLMAN AND K.L. COOKE, Differential-difference Equations, Acad. Press, New York, 1963. [2] I. BIHARI, A generalization of a lemma of Bellman and its application to uniqueness problems of differential equations, Acta Math. Acad. Sci. Hungar., 7 (1956), 71–94. [3] H. EL-OWAIDY, A. RAGAB AND A. ABDELDAIM, On some new integral inequalities of Growall Bellman type, Appl. Math. Comput., 106(2-3) (1999), 289–303. [4] V. LAKSHIMIKANTHAM AND S. LEELA, Differential and Integral Inequalities: Theory and Applications, Academic Press, New York/London,1969. [5] F.W. MENG AND W.N. LI, On some new integral inequalities and their applications, Appl. Math. Comput., 148 (2004), 381–392. [6] B.G. PACHPATTE, Inequalities for Differential and Integral Equations, Academic Press, San Diego, 1998. [7] B.G. PACHPATTE, Explicit bounds on certain integral inequalities, J. Math. Anal. and Applics., 267(1) (2002), 48–61. Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits Man-chun Tan and En-hao Yang Title Page Contents JJ J II I Go Back Close [8] H.M. RODRIGUES, On growth and decay of solutions of perturbed retarded linear equations, Tohoku Math. J., 32 (1980), 593–605. [9] EN-HAO YANG, Generalizations of Pachpatte’s integral and discrete inequalities, An. Diff. Eqs., 13(2) (1997), 180–188. Quit Page 19 of 20 J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au [10] EN-HAO YANG, On some nonlinear integral and discrete inequalities related to Ou-Iang’s inequality, Acta Math. Sinica., New Series, 14(3) (1998), 353–360. Estimation for Bounded Solutions of Integral Inequalities Involving Infinite Integration Limits Man-chun Tan and En-hao Yang Title Page Contents JJ J II I Go Back Close Quit Page 20 of 20 J. Ineq. Pure and Appl. Math. 7(5) Art. 189, 2006 http://jipam.vu.edu.au