**calculate 计算**

To determine or ascertain by mathematical methods; compute.

**calculator 计算器**

An electronic or mechanical device for the performance of mathematical computations.

**calculus 微积分**

The branch of mathematics that deals with limits and rates of change, includs differential calculus, integral calculus.

**calendar 日历**

A table or series of pages showing the months, weeks, and days in at least one specific year.

**capacity 容量**

The maximum amount or number that can be received or contained; cubic contents; volume.

**cardinal number, cardinality 基数**

Any of the numbers that express amount, as 1, 57, 214, denoting quantity but not order in a set.

**Cartesian coordinates 直角坐标系, 笛卡尔坐标**

A system of representing points in space in terms of their distance from a given origin measured along a set of mutually perpendicular axes. Written (x,y,z) with reference to three axes.

**Celsius 摄氏**

Of or relating to a temperature scale that registers the freezing point of water as 0° and the boiling point as 100° under normal atmospheric pressure.

**census 人口调查**

An official enumeration of the population, with details as to age, sex, occupation, etc.

**cent 一分钱**

A coin and unit of money worth 1% of the main unit of money in many countries, for example of the US dollar or of the euro.

**center | centre 中心**

The middle point, as the point within a circle or sphere equally distant from all points of the circumference or surface, or the point within a regular polygon equally distant from the vertices.

**Centigrade 摄氏**

Because of confusion over the prefix centi-, which originally meant 100 but developed the meaning 1/100, scientists agreed to stop using the term centigrade in 1948. They use the term Celsius instead.

**centimeter 厘米**

A unit of length equal to one hundredth (1/100) of a meter.

**centroid 形心，质心**

The centre of mass of an object of uniform density, esp of a geometric figure.

**century 一百年**

A period of 100 years.

**chord 弦**

A line segment that joins two points on a curve.

**circle 圆**

With center (a, b) and radius r is the locus of all points in the plane whose distance from the center is equal to r.

### x^{2} + y^{2} = r^{2}

### (x – a)^{2} + (y – b)^{2} = r^{2}

**circumcenter 外心**

The center of a circumcircle where perpendicular bisectors of the sides of a polygon inscribed in the circle intersect.

**circumcircle 外接圆**

A circle that passes through all the vertices of a polygon.

**circumference 圆周**

The length of a closed geometric curve, esp of a circle. The circumference of a circle is equal to the diameter multiplied by π.

**circumradius 外接圆半径**

The radius of a circle that is circumscribed about a polygon.

**circumscribe 外接**

To draw one geometric figure around another so that they touch at every corner of the enclosed figure without cutting across each other, so that the two are in contact but do not intersect.

**classify 分类**

To arrange or organize according to class or category.

**clockwise 顺时针方向**

In the same direction as the hands of a clock rotate.

**closed curve 封闭曲线**

A curve having no endpoints, such as a circle.

**cluster 簇，丛**

A group of the same or similar elements gathered or occurring closely together.

**codomain 值域**

The set of values that a function is allowed to take.

**coefficient 系数**

A number or symbol multiplied with a variable or an unknown quantity in an algebraic term, as 4 in the term 4x, or x in the term x(a + b).

**cofactor 余子式**

Equal to (-1)i+j times the minor (The determinant of the matrix obtained by deleting the i-th row and j-th column of the matrix).

**coincident 重合**

Matching point for point, occupying the same place or position.

**collinear 共线**

Lying on or passing through a single straight line.

**column 柱；圆柱**

- An upright post or pillar usually having a cylindrical shaft, a base, and a capital.
- A vertical array of numbers or mathematical terms.

**column graph / column chart 柱状图**

**combination 组合**

- An arrangement of the numbers, terms, etc, of a set into specified groups without regard to order in the group.
- A group formed in this way. The number of combinations of n objects taken r at a time is n!/[(n – r)!r!]. Symbol:
_{n}C_{r}

**commission 佣金**

An amount of money that is paid to sb for selling goods and which increases with the amount of goods that are sold.

**common denominator 公分母**

A quantity into which all the denominators of a set of fractions may be divided without a remainder.

**common difference 公差**

The difference between any two consecutive terms in an arithmetic progression.

**common factor 公因数**

A number or quantity that is a factor of each member of a group of numbers or quantities: 5 is a common factor of 15 and 20. Also called: common divisor.

**common fraction 简分数，普通分数**

A fraction represented as a numerator above and a denominator below a horizontal or diagonal line. Another name for simple fraction.

**commutative law 交换律**

A rule which requires that the result of a binary operation be independent of order; that is, a+b = b+a, ab = ba.

**compass 圆规；指南针**

- Also called: pair of compasses an instrument used for drawing circles, measuring distances, etc, that consists of two arms, joined at one end, one arm of which serves as a pivot or stationary reference point, while the other is extended or describes a circle.

- An instrument for determining directions, as by means of a freely rotating magnetized needle that indicates magnetic north.

**compass points 罗盘方位, 罗盘指标**

Eight, 16, or 32 named directions, comprising cardinal, quadrantal, and 24 intermediate points.

**complement 补充; 补集**

- Something that completes, makes up a whole, or brings to perfection.
- For a universal set, the set of all elements in the set that are not in a specified subset.

**complementary angle 余角**

The angle that, when added to a specified angle, produces a right angle.

**complex number 复数**

A number of the form a + bi, which containing both a real number and an imaginary number.

**composite number 合数**

An integer exactly divisible by at least one positive integer other than itself or 1.

**compound interest 复利**

Interest that is paid both on the original amount of money saved and on the interest that has been added to it.

**computation 计算**

An act or the process of calculating something.

**computer 计算机，电脑**

A programmable electronic device designed to accept data, perform prescribed mathematical and logical operations at high speed, and display the results of these operations. Mainframes, desktop and laptop computers, tablets, and smartphones are some of the different types of computers.

**concave 凹**

- Curved like the inner surface of a sphere.
- A polygon containing an interior angle greater than 180°.

**concentric circles 同心圆**

A family of coplanar circles with the same center.

**cone 圆锥体**

Surface generated by a moving line (the generator) that passes through a given fixed point (the vertex) and continually intersects a given fixed curve (the directrix). The generator creates two conical surfaces—one above and one below the vertex—called nappes. If the directing curve is a conic section (e.g., a circle or ellipse) the cone is called a quadric cone. The most common type of cone is the right circular cone, a quadric cone in which the directrix is a circle and the line drawn from the vertex to the center of the circle is perpendicular to the circle. The generator of a cone in any of its positions is called an element.

**congruent 全等**

Having the same size and shape.

**conic section 圆锥曲线**

Formed by the intersection of a plane and a right circular cone (conical surface). The ordinary conic sections are the circle, the ellipse, the parabola, and the hyperbola.

**conjugate 共轭**

- (Of two angles) having a sum of 360°.
- (Of two complex numbers) differing only in the sign of the imaginary part as 4 + 3i and 4 – 3i.
- (Of two algebraic numbers) being roots of the same irreducible algebraic equation with rational coefficients.
- (Of two elements of a square matrix) interchanged when the rows and columns are interchanged.
- (Of two arcs) forming a complete circle or other closed curved figure.

**constant 常数，恒量**

A mathematical quantity that retains a fixed value in any circumstances or throughout a particular set of calculations.

**construction 结构；构造**

A drawing of a line, angle, or figure satisfying certain conditions, used in solving a problem or proving a theorem.

**continuous data 连续数据**

Statistics or other information represented in a form suitable for processing by computer.

**converge 收敛**

To approach a finite limit as the number of terms increases.

**convex 凸**

- Having a surface or boundary that curves or bulges outward, as the exterior of a sphere.
- A polygon) having all interior angles less than or equal to 180°.

**coordinate plane 坐标平面**

A coordinate system in which the coordinates of a point are its distances from a set of perpendicular lines that intersect at an origin, such as two lines in a plane or three in space.

**coordinates 坐标**

Any of a set of two or more numbers used to determine the position of a point, line, curve, or plane in a space of a given dimension with respect to a system of lines or other fixed references.

**coplanar 共面**

Lying or occurring in the same plane.

**corresponding angles 同位角**

Two nonadjacent angles made by the crossing of two lines by a third line, one angle being interior, the other exterior, and both being on the same side of the third line.

**cosecant 余割**

A trigonometric function that in a right-angled triangle is the ratio of the length of the hypotenuse to that of the opposite side; the reciprocal of sine.

**cosine 余弦**

- In a right triangle, the ratio of the length of the side adjacent to an acute angle to the length of the hypotenuse.
- The abscissa at the endpoint of an arc of a unit circle centered at the origin of a Cartesian coordinate system, the arc being of length x and measured counterclockwise from the point (1, 0) if x is positive or clockwise if x is negative.

**cotangent 余切**

A trigonometric function that in a right-angled triangle is the ratio of the length of the adjacent side to that of the opposite side; the reciprocal of tangent.

**counterclockwise 逆时针**

In a direction opposite to the rotating hands of a clock.

**counting number 自然数**

A natural number.

**credit 信用，贷款**

- An arrangement for deferred payment of a loan or purchase.
- The positive balance or amount remaining in a person’s account.

**cross multiply 交叉相乘**

To remove fractions from an equation by multiplying each side by the common multiple of the denominators of the fractions of both sides.

**cross section 截面**

A section formed by a plane cutting through an object, usually at right angles to an axis.

**cube 立方体; 三次幂**

- A solid bounded by six equal squares, the angle between any two adjacent faces being a right angle.
- The third power of a quantity, expressed as a
^{3}= a·a·a.

**cube root 立方根**

A number whose cube is equal to a given number: 2 is the cube root of 8.

**cubic centimeter 立方厘米**

A unit of volume or capacity equal to one thousandth (10^{-3}) of a liter or to one milliliter.

**cubic measure 立方单位制，体积量度单位**

The measurement of volume or space by means of cubic units.

**cubic meter 立方米**

A metric unit of volume or capacity equal to 1000 liters.

**cuboid 长方体；长方体的**

A geometric solid whose six faces are rectangles; rectangular parallelepiped.

**curve 曲线；弧形；弯曲**

A continuously bending line, without angles.

**curved line 曲线**

**cylinder 圆柱，柱面**

A right circular cylinder having a finite height with circular ends perpendicular to the axis as shown in the figure. If the ends are open, it is called an open cylinder. If the ends are closed by flat surfaces it is called a solid cylinder.