Geometrical solutions of some quadratic equations with non-real roots

This note gives geometrical/graphical methods of finding solutions of the quadratic equation ax ² + bx + c = 0, a p 0, with non-real roots. Three different cases which give rise to non-real roots of the quadratic equation have been discussed. In case I a geometrical construction and its proof for finding the solutions of the quadratic equation ax ² + bx + c = 0, a p 0, when a,b,c ] R, the set of real numbers, are presented. Case II deals with the geometrical solutions of the quadratic equation ax ² + bx + c = 0, a p 0, when b ] R, the set of real numbers; and a,c ] C, the set of complex numbers. Finally, the solutions of the quadratic equation ax ² + bx + c = 0, a p 0, when a,c ] R, the set of real numbers, and b ] C, the set of complex numbers, are presented in case III.     

Geometrical solution of some cubic equations with non-real roots

A general cubic equation ax ³ + bx ² + cx + d = 0 where a, b, c, d ∈R, a ≠ 0 has three roots with two possibilities—either all three roots are real or one root is real and the remaining two roots are imaginary. Dealing with the second possibility this paper attempts to give the geometrical locations of the imaginary roots of the equation under three different sets of conditions. These sets of conditions include: (i) the real root of the given cubic equation is given, (ii) the real part of an imaginary root is given, and (iii) the imaginary part of an imaginary root is given.     

Solvability of cubic equations in p-ADIC integers (p > 3)

We give a criterion for the existence of solutions to an equation of the form x ³ + ax = b, where a, b ∈ ? _p , in p-adic integers for p > 3. Moreover, in the case when the equation x ³ + ax = b is solvable, we give necessary and sufficient recurrent conditions on a p-adic number x ∈ ?* _p under which x is a solution to the equation.     

Equal values of trinomials revisited

A necessary and sufficient condition is given for an equation ax ^m + bx ⁿ + c = dy ^p + ey ^q to have infinitely many rational solutions with a bounded denominator, under the assumption that m > n > 0, p > q > 0, ab ≠ 0 ≠ de and either m > p > 2, or m = p > 2 and n ≥ q. In a previous paper there was an additional assumption (m, n) = (p, q) = 1.     

Functions of Two Variables with Large Tangent Plane Sets

We show that there exist a C¹function,f, of two variables and a setE ⊆ R²of zero Lebesgue measure such that using the natural three-dimensional parametrization of planesz = ax + by + ctangent to the surfacez = f(x, y), the (three-dimensional) interior of the set of parameter values, (a, b, c), of tangent planes corresponding to points (x, y) inEis nonempty. From the Morse–Sard theorem it follows that there are no such C²functions. We also study briefly the relationship of our example with the Denjoy–Young–Saks theorem.     

Imaginary-quadratic solutions of anti-Vandermonde systems in 4 unknowns and the Galois orbits of trees of diameter 4

The paper is devoted to an elementary Diophantine problem motivated by Grothendieck’s dessins d’enfants theory. Namely, we consider the system of equations ax ^j + by ^j + cz ^j + dt ^j = 0 (j = 1, 2, 3) with natural a, b, c, and d. For trivial reasons it has no real (hence rational) nonzero solutions; we study the cases where it has imaginary quadratic ones. We suggest an infinite family of such cases covering all the imaginary quadratic fields. We discuss this result from the viewpoint of the Galois orbits of trees of diameter 4. __________ Translated from Fundamentalnaya i Prikladnaya Matematika, Vol. 9, No. 3, pp. 229–236, 2003.     

Boundedness of Solutions in Asymmetric Oscillations via the Twist Theorem

In this paper we consider the boundedness of all the solutions for the equation x″ + ax ⁺−bx ⁻ = f(t) is a smooth 2π-periodic function, a and b are positive constants (a≠b). Received November 27, 1998, Accepted October 15, 1999     

关于一类高次不定方程的解

本文得到了方程(axⁿ±c)/(ax^m±c)=y²+1,c=1,2,4适合m≡n(mod2)的全部解.     

On the Diophantine equation ax + by = ck

In this paper we investigate the solvability and the representation of the solutions of the equation ax² +by² = ckⁿ. We extend and improve many known results. In particular, we completely solve the equation (a ± 1)x² + (3a ? 1) = 4aⁿ, 2 ? n.     

On the Solutions of a Second Order Differential Equation Arising in the Theory of Resonant Oscillations in a Tank

The properties of the solutions of the differential equation y″ = y² ? x² ? c subject to the condition that y is bounded for all finite x discussed. The arguments of Holmes and Spence have been used by Ockendon, Ockendon, and Johnson to show that there are no solutions if c is large and negative. Numerically we find that solutions exist provided c is greater than a critical value c* and estimate this value to be c* = ?…. As x tends to + ∞ the solutions are asymptotic to . The relation between A₊ and ?₊ are found analytically as A₊ → ∞. This problem arises as a connection problem in the theory of resonant oscillations of water waves.     

The evaluation of a quartic integral via Schwinger, Schur and Bessel

We provide additional methods for the evaluation of the integral

Relations between roots and coefficients of cubic equations with one root negative the reciprocal of another

Under predetermined conditions on the roots and coefficients, necessary and sufficient conditions relating the coefficients of a given cubic equation x ³?+?ax ²?+?bx?+?c?=?0 can be established so that the roots possess desired properties. In this note, the condition for one root of a cubic equation to be the negative reciprocal of another one is obtained. Given that the coefficients a, b, c of the cubic equation are in arithmetical or geometrical progression, further conditions are deived for one root to be the negative reciprocal of another. These results provide useful means for checking calculated roots of cubic equations and could serve the needs of teachers and students of Mathematical Sciences in tertiary institutions when the solution of cubic equations are first studied.     

On Legendre's equation ax2 + by2 + cz2 = 0

Let a, b, c be nonzero integers having no prime factors ≡ 3 (mod 4), not all of the same sign, abc squarefree, and for which Legendre's equation ax² + by² + cz² = 0 is solvable in nonzero integers x, y, z. A property is proved yielding a congruence which must be satisfied by any solution x, y, z.     

Proportionally modular diophantine inequalities and their multiplicity

Let I be an interval of positive rational numbers. Then the set S （I） = T ∩ N, where T is the submonoid of （Q0＋, ＋） generated by T, is a numerical semigroup. These numerical semigroups are called proportionally modular and can be characterized as the set of integer solutions of a Diophantine inequality of the form ax rood b 〈 cx. In this paper we are interested in the study of the maximal intervals I subject to the condition that S （I） has a given multiplicity. We also characterize the numerical semigroups associated with these maximal intervals.     

Markoff–Rosenberger triples in geometric progression

We study solutions of the Markoff–Rosenberger equation ax ²+by ²+cz ²=dxyz whose coordinates belong to the ring of integers of a number field and form a geometric progression.     

A polynomial <Emphasis Type="Italic">p</Emphasis>-adic dynamical system

We completely describe the Siegel discs and attractors for the p-adic dynamical system f(x) = x ²ⁿ⁺¹ + axⁿ⁺¹ on the space of complex p-adic numbers.     

On the Diophantine System a^2 ＋ b^2 = c^3 and a^x ＋ b^y = c^z for b is an Odd Prime

Let a, b and c be fixed coprime positive integers. In this paper we prove that if a^2 ＋ b^2 = c^3 and b is an odd prime, then the equation a^x ＋ b^y = c^z has only the positive integer solution （x, y, z） = （2,2,3）.