Looking for math words that start with D?

From Data to Duodecimal there are some great words beginning with the letter D that are used in mathematics, geometry, and other number-related sciences.

Here is a list of some of the most common or interesting math-related words starting with D:

## Math Words That Start With D

**Data **– a collection of information. gathered by observation, questioning or measurement.

**De Moivre’s Theorem **– de Moivre’s formula states that for any real number x and integer n it holds that {\displaystyle {\big }^{n}=\cos nx+i\sin nx, } where i is the imaginary unit.

**Decagon **– a closed shape with ten sides and ten angles.

**Deciles **– a quantitative method of splitting up a set of ranked data into 10 equally large subsections.

**Decimal **– A decimal is a way of writing a number that is not whole. Decimal numbers are ‘in between’ numbers.

**Decrease **– the process of growing progressively less (as in size, amount, number, or intensity)

**Definite Integral **– A definite integral is a formal calculation of area beneath a function, using infinitesimal slivers or stripes of the region.

**Degenerate **– a limiting case of a class of objects which appears to be qualitatively different from (and usually simpler than) the rest of the class, and the term degeneracy is the condition of being a degenerate case.

**Degree (Angle Measure)** – an angle measure can be defined as the measure of the angle formed by the two rays or arms at a common vertex.

**Del Operator **– an operator used in mathematics (particularly in vector calculus) as a vector differential operator, usually represented by the nabla symbol.

**Delta **– Delta is the fourth letter of the Greek alphabet. In the system of Greek numerals it has a value of 4.

**Denominator **– the part of a fraction that is below the line and that functions as the divisor of the numerator.

**Density **– the mass of an object divided by its volume.

**Dependent Variable **– The dependent variable is the one that depends on the value of some other number.

**Derivative **– the derivative of a function of a real variable measures the sensitivity to change of the function value with respect to a change in its argument.

**Descartes’ Rule Of Signs** – Descartes’ rule of signs, first described by René Descartes in his work La Géométrie, is a technique for getting information on the number of positive real roots of a polynomial.

**Determinant **– a scalar value that is a function of the entries of a square matrix.

**Deviation **– a measure of difference between the observed value of a variable and some other value, often that variable’s mean.

**Diagonal Matrix **– In linear algebra, a diagonal matrix is a matrix in which the entries outside the main diagonal are all zero; the term usually refers to square matrices.

**Diagram **– a figure, usually consisting of a line drawing, made to accompany and illustrate a geometrical theorem, mathematical demonstration, etc.

**Diameter **– In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle.

**Diametrically Opposed** – means completely and totally opposed in the opposite direction, as on the opposite sides of a diameter.

**Difference **– To find the difference between two numbers, subtract the number with the smallest value from the number with the largest value.

**Differentiation **– the process of finding the derivative, or rate of change, of a function.

**Digit **– any of the numerals from 0 to 9, especially when forming part of a number.

**Dihedral Angle **– defined as the angle between two planes, both of which pass through the same bond.

**Dilation **– a transformation that changes the size of a figure.

**Dimensions **– the measure of the size of an object, such as a box, usually given as length, width, and height.

**Dipyramid **– Another name for Bipyramid.

**Direct Proportion** – Two quantities are said to be in direct proportion if they increase or decrease in the same ratio.

**Direct Variation **– mathematical relationship between two variables that can be expressed by an equation in which one variable is equal to a constant times the other.

**Discontinuity **– The function of the graph which is not connected with each other is known as a discontinuous function.

**Discontinuous Function** – functions that are not a continuous curve – there is a hole or jump in the graph.

**Discrete **– the branch of mathematics dealing with objects that can assume only distinct, separated values.

**Disjoint Events **– Disjoint events cannot happen at the same time. In other words, they are mutually exclusive.

**Disjunction **– a compound statement formed by combining two statements using the word or.

**Disk Method **– the process of finding the volume of an object by dividing that object into many small cylinders/disks and then adding the volumes of these small disks together.

**Distance Formula **– Algebraic expression that gives the distances between pairs of points in terms of their coordinates.

**Distribute **– the distributive property helps simplify difficult problems because it breaks down expressions into the sum or difference of two numbers.

**Divergent Sequence **– an infinite series that is not convergent, meaning that the infinite sequence of the partial sums of the series does not have a finite limit.

**Dividend **– the number in an equation that is to be divided when problem-solving.

**Division **– a simple operation in which a number is divided.

**Dodecagon **– a 12-sided polygon.

**Dodecahedron **– any polyhedron with twelve flat faces.

**Domain **– the domain of a function is the set of inputs accepted by the function.

**Dot Product **– the dot product or scalar product is an algebraic operation that takes two equal-length sequences of numbers, and returns a single number.

**Double Cone **– complete cone formed by straight lines through the vertex, the straight lines being indefinitely extended in both directions —opposed to half cone.

**Double Root **– a root that appears twice in the solution of an algebraic equation.

**Doubling Time **– the time it takes for a population to double in size/value.

**Duodecimal **– The duodecimal system (also known as base 12, dozenal, or, rarely, uncial) is a positional notation numeral system using twelve as its base.

I hope you found the words you were looking for from the list above.

This isn’t an exhaustive list, if there are any math words starting with the letter D that you would like added to the list, please leave me a comment below.

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*Image credits – Photo by Joshua Hoehne on Unsplash*