﻿ ﻿﻿﻿ 以 d 开头的数学词汇 | 玄数
﻿﻿

## 以 d 开头的数学词汇

2012-10-07
data   数据

• The observations gathered from an experiment, survey or observational study. Often the data are a randomly selected sample from an underlying population.
• Statistics or other information represented in a form suitable for processing by computer.

date   日期
A particular month, day, and year at which some event happened or will happen.

A period of ten years, especially a continuous period, such as 1910~1919 or 2009~2018.

decagon   十边形
A polygon with ten sides and ten angles.

decahedron   十面体
A solid figure having ten plane faces.

decimal   十进制
A number written using the base 10.

12345 = 1×105 + 2×104 + 3×103 + 4×102 + 5×100

decimal fraction   十进制分数，小数
A fraction whose denominator is some power of 10, usually indicated by a dot (decimal point or point) written before the numerator: as 0.4 = 4/10; 0.126 = 126/1000.

decimal number system   十进制数字系统
A positional system of numeration that uses decimal digits and a base of ten.

decimal point   小数点
A dot written in a decimal number, as in 8.6, to indicate the place where values change from positive to negative powers of 10.

decrease   减少
To become or cause to become less or smaller, as in number, amount, or intensity.

deduct   扣除
To take away (a quantity) from another; subtract.

degree   度

• A unit for measuring angles, equal to 1/360 of a complete revolution.
• A unit of latitude or longitude, equal to 1/360 of a great circle.
• A unit for measuring temperature.
• The highest power or the sum of the powers of any term in a polynomial or by itself: x4 + x + 3 and xyz2 are of the fourth degree.
• The greatest power of the highest order derivative in a differential equation.

denominator   分母
The expression written below the line in a common fraction that indicates the number of parts into which one whole is divided. For example, 8 is the denominator of 5/8.

density   浓度; 密度

• The quantity of something per unit measure, especially per unit length, area, or volume.
• The mass per unit volume of a substance under specified conditions of pressure and temperature.

dependent event   相关事件，相依事件
Two events are dependent if the outcome or occurrence of the first affects the outcome or occurrence of the second so that the probability is changed.

descending order   降序
Numbers are arranged from the largest to the smallest number. E.g. 25, 21, 17, 13 and 9 are arranged in descending order.

determinant 行列式
The value computed from a square matrix of numbers by a rule of combining products of the matrixentries and that characterizes the solvablitity of simultaneous linear equations.

diagonal   对角线

• Joining two nonadjacent vertices of a polygon.
• Joining two vertices of a polyhedron not in the same face.

diagram   图表

• A drawing or plan that outlines and explains the parts, operation, etc.
• A graphic representation of an algebraic or geometric relationship.

diameter   直径
A straight line segment passing through the center of a figure, especially of a circle or sphere, and terminating at the periphery.

diamond   菱形; （纸牌的）方块

• An equilateral quadrilateral, especially as placed with its diagonals vertical and horizontal; a lozenge or rhombus.
• One of the four suits (= sets) in a pack/deck of cards. The cards are marked with red diamond shapes.

dice   骰子
Small cubes of plastic, ivory, bone, or wood, marked on each side with one to six spots, usually used in pairs in games of chance or in gambling.

difference   差

• The amount by which one quantity is greater or less than another.
• The amount that remains after one quantity is subtracted from another.

difference of two Squares   平方差
Squared (multiplied by itself) number subtracted from another squared number. Every difference of squares may be factored according to the identity. a2 – b2 = (a+b)(a-b)

digit   数字
Any of the numbers from 0 to 9.

digital clock / digital watch   数字时钟
A clock that displays the time in numerical digits rather than by hands on a dial.

dilation   扩张
The act of expanding or enlarging or the state of being expanded or enlarged.

dimension   尺寸; 维度

• A measure of spatial extent, especially width, height, or length.
• The number of coordinates required to locate a point in space.

directed number   有向数, 有符号数
A number together with a sign.

direction   方向

• The point or region itself.
• A position on a line extending from a specific point toward a point of the compass or toward the nadir or the zenith.

discount   折扣

• To sell or offer for sale at a reduced price.
• To reduce in quantity or value.

discrete data   离散数据
Statistics or other information represented in a form suitable for processing by computer.

displacement   位移
The distance measured in a particular direction from a reference point. Symbol: s.

distance   距离
The length of the shortest line segment joining two points, or a straight line or curve.

distributive law   分配律
To expand (an expression containing two operators) in such a way that the precedence of the operators is changed; for example, distributing multiplication over addition in a(b + c) yields ab + ac.

divide   除，划分
To separate into equal parts by the process of mathematical division; apply the mathematical process of division to: Eight divided by four is two.

dividend   被除数；股利
A quantity to be divided.

divisible   整除
Capable of being divided, especially with no remainder: 15 is divisible by 3 and 5.

division   除法
The operation of determining how many times one quantity is contained in another; the inverse of multiplication.

dodecagon   十二边形
A polygon with 12 sides and 12 angles.

dodecahedron   十二面体
A polyhedron with 12 faces.

dollar   美元
The unit of money in the US, Canada, Australia and several other countries. Symbol: \$.

domain of a function   函数的定义域
The set of values of the independent variable for which a function is defined.

double   两倍
Twice as much in size, strength, number, or amount: a double dose.

dozen   十二，一打
A group of twelve of the same thing.

﻿