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.

If you’d like to explore more math words starting with different letters of the alphabet, click any of the letters below to go to the list for that letter:

*Image credits – Photo by Joshua Hoehne on Unsplash*

Phil lives in England, UK, and has around 20 years experience as a professional life, career and executive coach. He started this blog to help others find and define their own self development journey. Blogging about a wide range of topics to help facilitate a better future.