ACCA, MBA, Tax Agent ជាអ្នកនិពន្ធហើយអាចប្រលងជាប់៖ ACCA រហូត ៤ មុខវិជ្ជាក្នុងពេលតែម្តង, Tax Agent ពិន្ទុខ្ពស់, MBA & BBA ជាប់ជាសិស្សពូកែ និងមានបទពិសោធការងារជាង ១៥ ឆ្នាំ ព្រមទាំងអ្នកនិពន្ធផ្សេងៗ ?ទិញឯកសារហើយ អានមិនយល់អាចសួរបាន
Distributive property: property whereby summing two numbers and then multiplying by another number yields the same value as multiplying both values by the other value and then adding them together, e.g. a(b + c) = ab + ac
Element: a member of, or an object in, a set
Diophantine equation: a polynomial equation with integer coefficients that also allows the variables and solutions to be integers only
Differentiation: the operation in calculus (inverse to the operation of integration) of finding the derivative of a function or equation
Differential geometry: a field of mathematics that uses the methods of differential and integral calculus (as well as linear and multilinear algebra) to study the geometry of curves and surfaces
Differential equation: an equation that expresses a relationship between a function and its derivative, the solution of which is not a single value but a function (has many applications in engineering, physics economics, etc)
Deductive reasoning or logic: a type of reasoning where the truth of a conclusion necessarily follows from, or is a logical consequence of, the truth of the premises (as opposed to inductive reasoning)
Derivative: a measure of how a function or curve changes as its input changes, i.e. the best linear approximation of the function at a particular input value, as represented by the slope of the tangent line to the graph of the function at that point, found by the operation of differentiation
Decimal number: a real number which expresses fractions on the base 10 standard numbering system using place value, e.g. 37⁄100 = 0.37
Cubic equation: a polynomial having a degree of 3 (i.e. the highest power is 3), of the form ax3 + bx2 + cx + d = 0, which can be solved by factorization or formula to find its three roots
Correlation: a measure of relationship between two variables or sets of data, a positive correlation coefficient indicating that one variable tends to increase or decrease as the other does, and a negative correlation coefficient indicating that one variable tends to increase as the other decreases and vice versa
Coordinate plane: a plane with two scaled perpendicular lines that intersect at the origin, usually designated x (horizontal axis) and y (vertical axis)
Coordinate: the ordered pair that gives the location or position of a point on a coordinate plane, determined by the point’s distance from the x and y axes, e.g. (2, 3.7) or (-5, 4)
Continued fraction: a fraction whose denominator contains a fraction, whose denominator in turn contains a fraction, etc, etc
Conic section: the section or curve formed by the intersection of a plane and a cone (or conical surface), depending on the angle of the plane it could be an ellipse, a hyperbola or a parabola
Congruence: two geometrical figures are congruent to one another if they have the same size and shape, and so one can be transformed into the other by a combination of translation, rotation and reflection
Composite number: a number with at least one other factor besides itself and one, i.e. not a prime number
Complex number: a number expressed as an ordered pair comprising a real number and an imaginary number, written in the form a + bi, where a and b are real numbers, and i is the imaginary unit (equal to the square root of -1)
Complex dynamics: the study of mathematical models and dynamical systems defined by iteration of functions on complex number spaces
Combinatorics: the study of different combinations and groupings of numbers, often used in probability and statistics, as well as in scheduling problems and Sudoku puzzles
Coefficients: the factors of the terms (i.e. the numbers in front of the letters) in a mathematical expression or equation, e.g. in the expression 4x + 5y2 + 3z, the coefficients for x, y2 and z are 4, 5 and 3 respectively
Cartesian coordinates: a pair of numerical coordinates which specify the position of a point on a plane based on its distance from the the two fixed perpendicular axes (which, with their positive and negative values, split the plane up into four quadrants)
Cardinal numbers: numbers used to measure the cardinality or size (but not the order) of sets – the cardinality of a finite set is just a natural number indicating the number of elements in the set; the sizes of infinite sets are described by transfinite cardinal numbers, r0 (aleph-null), r1 (aleph-one), etc
Calculus of variations: an extension of calculus used to search for a function which minimizes a certain functional (a functional is a function of a function)
Boolean algebra or logic: a type of algebra which can be applied to the solution of logical problems and mathematical functions, in which the variables are logical rather than numerical, and in which the only operators are AND, OR and NOT
Calculus (infinitesimal calculus): a branch of mathematics involving derivatives and integrals, used to study motion and changing values
Bnomial coefficients: the coefficients of the polynomial expansion of a binomial power of the form (x + y) n, which can be arranged geometrically according to the binomioal theorem as a symmetrical triangle of numbers known as Pascal’s Triangle, e.g. (x + y)4 = x4 + 4x3y + 6x2y2 + 4xy3 + y4 the coefficients are 1, 4, 6, 4, 1
Binomial: a polynomial algebraic expression or equation with just two terms, e.g. 2x3 – 3y = 7; x2 + 4x; etc
Bijection: a one-to-one comparison or correspondence of the members of two sets, so that there are no unmapped elements in either set, which are therefore of the same size and cardinality
Bell curve: the shape of the graph that indicates a normal distribution in probability and statistics
Bayesian probability: a popular interpretation of probability which evaluates the probability of a hypothesis by specifying some prior probability, and then updating in the light of new relevant data
Base n: the number of unique digits (including zero) that a positional numeral system uses to represent numbers, e.g. base 10 (decimal) uses 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 in each place value position; base 2 (binary) uses just 0 and 1; base 60 (sexagesimal, as used in ancient Mesopotamia) uses all the numbers from 0 to 59; etc
Axiom: a proposition that is not actually proved or demonstrated, but is considered to be self-evident and universally accepted as a starting point for deducing and inferring other truths and theorems, without any need of proof
Asymptote: a line that the curve of a function tends towards as the independent variable of the curve approaches some limit (usually infinity) i.e. the distance between the curve and the line approaches zero
Arithmetic: the part of mathematics that studies quantity, especially as the result of combining numbers (as opposed to variables) using the traditional operations of addition, subtraction, multiplication and division (the more advanced manipulation of numbers is usually known as number theory)
Associative property: property (which applies both to multiplication and addition) by which numbers can be added or multiplied in any order and still yield the same value, e.g. (a + b) + c = a + (b + c) or (ab)c = a(bc)
Analysis (mathematical analysis): grounded in the rigorous formulation of calculus, analysis is the branch of pure mathematics concerned with the notion of a limit (whether of a sequence or of a function)
Analytic (Cartesian) geometry: the study of geometry using a coordinate system and the principles of algebra and analysis, thus defining geometrical shapes in a numerical way and extracting numerical information from that representation
Algorithm: a step by step procedure by which an operation can be carried out
Amicable numbers: pairs of numbers for which the sum of the divisors of one number equals the other number, e.g. 220 and 284, 1184 and 1210
Algebraic equation: a combination of numbers and letters equivalent to a sentence in language, e.g. y = x2 + 3x – 4
Abstract algebra: the area of modern mathematics that considers algebraic structures to be sets with operations defined on them, and extends algebraic concepts usually associated with the real number system to other more general systems, such as groups, rings, fields, modules and vector spaces
Algebra: a branch of mathematics that uses symbols or letters to represent variables, values or numbers, which can then be used to express operations and relationships and to solve equations
Zircon : A zirconium silicate mineral belonging to the group of nesosilicates. Its corresponding chemical formula is ZrSiO4.
Zeolite : Microporous, aluminosilicate minerals commonly used as adsorbents.
Ypresian : The oldest age or the lowest stratigraphic stage of the Eocene. It spans the time between ~56 Ma and ~49 Ma (million years ago).
Yellow cake :
A kind of uranium concentrate powder obtained from leach solutions in an intermediate step in the enrichment of uranium ores.
Young’s modulus:
In solid mechanics, a measure of the stiffness of an isotropic elastic material. It is defined as the ratio of the uniaxial stress over the uniaxial strain in the range of stress in which Hooke’s Law holds.
X-ray fluorescence (XRF) : The emission of characteristic “secondary” (or fluorescent) X-rays from a material that has been excited by bombarding with high-energy X-rays or gamma rays. The phenomenon is widely used for elemental analysis and chemical analysis of minerals.
Xyloid coal :
A soft brown fuel with characteristics that put it somewhere between coal and peat.
Xenotime : A rare earth phosphate mineral whose major component is yttrium orthophosphate (YPO4).
X-ray diffraction (XRD) : A method of determining the arrangement of atoms within a crystal, in which a beam of X-rays strikes a crystal and diffracts into many specific directions.
Wolframite : An iron manganese tungstate mineral with the chemical formula (Fe,Mn)WO4.
Xenolith : A rock fragment which becomes enveloped in a larger rock during the latter’s development and hardening. In geology, the term is almost exclusively used to describe inclusions in igneous rock during magma emplacement and eruption.
Vug : A small cavity in a rock filled or lined with crystals or minerals that are different from the host rock.
Wiggle trace : A graph that plots wave amplitudes (recorded by seismic reflection and borehole logging) as a function of time, with the positive peaks shaded in a single dark colour.
Volcanic : Rocks that have crystallised from magma poured out at the surface or introduced at shallow depth. They have cooled relatively rapidly, the grain size of the crystals is small, some part of the melt may solidify as glass, volatiles are lost and anhydrous minerals with high temperatures of crystallisation are present.
Volcanic bomb : Rounded or spindle-shaped rock of mainly basaltic composition ejected during eruptions.
Vitrophyre : See pitchstone.
Vitrinite : A group of macerals that are the most common component of coal.
Vergence : The direction of overturning of asymmetric folds, which matches the direction of thrusting.
Vermiculite : A hydrous silicate mineral that is classified as a phyllosilicate and that expands greatly when heated. Exfoliation occurs when the mineral is heated sufficiently.
Vein : A mineral filling of a fracture or other crack within a rock in a sheet-like or tabular shape.
Varve : An annual layer of sediment or sedimentary rock.
Variscan orogeny :
A geologic mountain-building event caused by Late Paleozoic continental collision between Euramerica (Laurussia) and Gondwana to form the supercontinent of Pangaea.
Vacuole : A bubble inclusion within mineral grains (typically monocrystalline quartz), filled with liquid, gas, or both liquid and gas. Vacuoles are randomly distributed in contrast to the oriented bubble trains of Boehm Lamellae.
Ultramafic :
Almost feldspar-free. Examples of ultramafic rocks include dunite, peridotite, and pyroxenite.
Urgonian : A shallow-water carbonate facies deposited along the northern margins of the Tethys Ocean during the Barremian and Aptian.
Turbidity current : A current of rapidly moving, sediment-laden water moving down a slope through water, or another fluid. The current moves because it has a higher density than the fluid through which it flows.
Tygerberg formation : A component of the PreCambrian Malmesbury group of South Africa
Tundra : A vast, flat, treeless Arctic region of Europe, Asia, and North America in which the subsoil is permanently frozen.
Turbidite : The deposit of a turbidity current.
Triclinic : In the triclinic system, the crystal is described by vectors of unequal length, and none of the three vectors are orthogonal to another.
Tuff : A rock formed of compacted volcanic fragments, some of which can be distinguished by the naked eye. If the fragments are larger than the rock grades into an agglomerate.
Trachyte : A fine-grained igneous rock type of intermediate composition, in most cases with little or no quartz, consisting largely of alkali-feldspars (sanidene or oligooclase) together with a small amount of coloured silicates such as diopside, horneblende, or mica.
Travertine : A terrestrial sedimentary rock formed by the precipitation of carbonate minerals from solution in ground and surface waters and/or geothermally heated hot springs.
Topography : The arrangement of the natural and artificial physical features of an area.
Tor : A large, free-standing residual mass (rock outcrop) that rises abruptly from the surrounding smooth and gentle slopes of a rounded hill summit or ridge crest.
Tillite : A type of sedimentary rock derived from glacial till which has been indurated or lithified by subsequent burial into solid rock.
Till :
Unsorted glacial sediment. Glacial drift is a general term for the coarsely graded and extremely heterogeneous sediments of glacial origin. Glacial till is that part of glacial drift which was deposited directly by the glacier.
Tethys Ocean : A prehistoric ocean that existed between the continents of Gondwana and Laurasia during the Mesozoic era before the opening of the Indian Ocean.
Tephra : Fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.
Tenacity : A mineral’s behavior when deformed or broken.
Talus:
A collection of broken rock fragments at the base of crags, mountain cliffs, volcanoes or valley shoulders that has accumulated through periodic rockfall from adjacent cliff faces. Landforms associated with these materials are often called talus deposits.