Math Terms StartingWith D

In this page math terms startingwith d we are going to see definitions of mathematical terms starting with the letter "D". We have listed out almost terms in math starting with D.In math also it is very important to know the meaning of many important words which are being used in the subject math.Each term is defined and examples are provided where ever it is necessary. Links are given for every words, by using this students can learn the meaning and its application more clearly.




In math data means combinations of items organized in rows and multiple variables organized in columns. Data are results of measurements and can be visualized using graphs and charts.


Decade is a period of 10 years.For example Decade of the 20th century.


math terms startingwith d

A polygon having 10 angles and 10 sides.


In geometry, decahedron is a polyhedron with 10 faces.


Decimal is a real number system based on 10. Examples are Roman numerals, Brahmi, numerals, Hindu-Arabic numerals and Chinese numerals.


The lower part of the fraction is called denominator. For example in 3/4, 4 is the denominator.

Deductive proof and deductive reasoning

In number theory, proof based on logical arguments that is justified by axioms or theorems. Deductive reasoning showing certain statements follow logically some stated assumptions.


A line segment that connects two non-consecutive vertices of a polygon.AC and BD are diagonals of the square ABCD


Division is nothing but splitting in to equal parts.Let us consider the following example.

Example: there are 8 biscuits, and 4 friends want to share them, how do they divide the biscuits?

Divisibility test

Divisibility Test is the topic in which we are going to see the shortcuts to predict one number is divisible by another number with out doing too much calculation.

Disjoint Sets

Two or more sets are said to be disjoint if they have no common elements.Disjoint-sets are also known as non overlapping sets.

For example:

A={2,4,6,8} and B={1,3,5,7}. Here A and B have no common element. So A and B are disjoint sets.

Day Arithmetic

Day Arithmetic is one of the important topic which is given some considerable weight age in SAT exam and other competitive exams.If the divisor m=7, then the arithmetic modulo 7 is called the day clock arithmetic. The remainders are 0,1,2,3,4,5,6 correspond to week days Sunday, Monday, Tuesday, Wednesday, Thursday and so on.

Different forms of numbers

In mathematics we have different forms of numbers. The classification of numbers are natural number, whole number,Integer, fractions, decimals, percents, irrational and rational numbers, real numbers and complex numbers.

Distance between two points

Distance Between Two Points (x ₁, y₁) and (x₂ , y₂)

√(x₂ - x₁) ² + (y₂ - y₁) ²

Double angle formulas

1.Sin 2A = 2 Sin A cos A

2 sin 2A = 2 tan A/(1+tan² A)

3.Cos 2A = cos² A - Sin² A

4.Cos 2A = 1 - 2Sin² A

5.Cos 2A = 2Cos² A - 1

6.cos 2A = (1-tan² A)/(1+tan² A)

7. tan 2A = 2 tan A/(1-tan² A)

8. sin²A = (1-Cos 2A)/2

9.Cos²A = (1+Cos 2A)/2

Division of polynomials

Division of polynomials involves two cases, the first one is simplification,which is reducing the fraction and the second one is long division.


Diameter is the line which connect two ends of the circle and passing through the center.

De Moivre's Theorem

For any rational number n cos nθ + is sin n
θ is the value or one of the values of

(cos θ + i sin θ)

Distance between parallel lines

We can use the the following to find the distance between two parallel lines ax + by + c₁ = 0 and ax + by + c₂ = 0

Diagonal matrix

In a diagonal matrix all the entries along the diagonal are zero.

Direct Variation

When two quantities are said to be in direct variation if one quantity increases,then the other also increases or when one quantity decreases,the other also decreases.

Definite Integrals

A basic concept of integral calculus is limit. Generally the concept integration is used to find area between curves within certain limit.

Differentiation of implicit function

When the relation between x and y is given by an equation in the form of f(x,y) = 0 and the equation is not easily solvable for y, then y is said to be implicit function.math terms startingwith d

These are the word in math terms startingwith d.

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