Mathematics Dictionary

Many terminologies can be confusing to students if they do not know their real meanings. Here is a list of main mathematical keywords and their meanings in brief

 

A

 

Absolute value equation:  Equation whose graph forms a V that opens up or down.

 

 

Absolute value inequality: Inequalities involving absolute value

 

 

Absolute value: A number’s distance from zero on a number line. (The absolute value of –4 is 4; the absolute value of 4 is 4.)

 

 

Absolute value: A number’s distance from zero on a number line (e.g., the absolute value of 2 and the absolute value of -2 are both 2, i.e., |2| = 2 and |-2| = 2).

 

 

Acute angle: an angle whose measure is greater than 0 but less than 90 degrees; see obtuse angle

 

 

Addition rule: The probability of any of one of several mutually exclusive events occurring is equal to the sum of their individual probabilities. A typical example is the probability of a baby to be homozygous or heterozygous for a Mendelian recessive disorder when both parents are carriers. This equals to 1/4 + 1/2 = 3/4. A baby can be either homozygous or heterozygous but not both of them at the same time; thus, these are mutually exclusive events (see also multiplication rule).

 

 

Additive inverse: The opposite of a number. (The additive inverse of 3 is –3.  The sum of a number and its additive inverse is zero.)

 

 

Additive inverse: Two numbers are additive inverses of each other if their sum is 0 (e.g., since -4 + 4 = 0, then -4 and 4 are additive inverses of each other).

 

 

Adjacent angles: 2 non-straight and nonzero angles that have a common side in the interior of the angle formed by the non-common sides

 

 

Age-standardized rate: An age-standardized rate is a weighted average of the age-specific rates, where the weights are the proportions of a standard population in the corresponding age groups. The potential confounding effect of age is removed when comparing age-standardized rates computed using the same standard population.

 

 

Algebra: A generalization of arithmetic in which symbols represent members of a specified set of numbers and are related by operations that hold for all numbers in the set

 

 

Algebraic expression: An expression that contains a variable    Ex.  X – 2

 

 

Algebraic expression: Numeral and/or variable joined by any combination of the four basic operations (+, -, x, /) and involving any power(s) of numeral and/or variable (e.g., 3-8, 7×4, 4+X, N-2, 3(4+8)-7).

 

 

Algebraic fraction: A fraction that contains a variable

 

 

Alternate exterior angles: exterior angles on alternate sides of the transversal (not on the same parallel line)

 

 

Alternate interior angles: Same as above, only with interior angles

 

 

Alternative hypothesis: In practice, this is the hypothesis that is being tested in an experiment. It is the conclusion that is reached when a null hypothesis is rejected. It is the opposite of null hypothesis, which states that there is a difference between the groups or something to that effect.

 

 

Altitude of a triangle: the perpendicular segment from a vertex to the line containing the opposite side of a triangle

 

 

Altitude: height

 

 

Angle bisector: a ray that is in the interior of an angle and forms two equal angles with the sides of that angle

 

 

Angle measure between a line and a plane: the smallest of the angles formed when a line intersects a plane

 

 

Angle side: one of the two rays forming an angle

 

 

Angle: the union of 2 rays that have the same endpoint; measured in degrees or radians (trig.); the five types of angles are zero, acute, right, obtuse, and straight

 

 

Associative Property: A property of addition or multiplication in which the regrouping of the addends or factors does not change the outcome of the operations [i.e., (a + b) + c = a + (b + c) and (ab)c = a(bc)].

 

 

Associative Property: If three are more numbers are added or multiplied, the numbers can be regrouped without changing the results.  Ex.  4 + (6 + 5) = (4 + 6) + 5

 

 

Assumptions: Certain conditions of the data that are required to be met for validity of a statistical test.

 

 

Axis: Either of two number lines used to form a coordinate grid

 

 

 

 

 B

 

Bar graph: A graph in which horizontal or vertical bars represent data

 

 

Base angle: the angle opposite one of the equilateral sides in an isosceles triangle

 

 

Base: the side of an isosceles triangle whose endpoints are the vertices of the base angles

 

 

Bernoulli distribution models the behavior of data taking just two distinct values (0 and 1).

 

 

Bias: An estimator for a parameter is unbiased if its expected value is the true value of the parameter. Otherwise, the estimator is biased.

 

 

Binary (dichotomous) variable: A discrete random variable that can only take two possible values (success or failure).

 

 

Binomial distribution: The binomial distribution gives the probability of obtaining exactly r successes in n independent trials, where there are two possible outcomes one of which is conventionally called success.

 

 

Binomial: An expression consisting of two terms connected by a plus or minus sign, such as4a + 6

 

 

Bisector of a segment: any plane, point or two-dimensional figure containing the the midpoint of the segment and no other points on that segment

 

 

Blocks: Homogeneous grouping of experimental units (subjects) in experimental design. Groups of experimental units that are relatively homogeneous in that the responses on two units within the same block are likely to be more similar than the responses on two units in different blocks.

 

 

 

 

 C

 

Cardinal numbers: The counting numbers (1, 2, 3…).

 

 

Categorical (nominal) variable: A variable that can be assigned to categories. A non-numerical (qualitative) variable measured on a (discrete) nominal scale such as gender, drug treatments, disease subtypes; or on an ordinal scale such as low, median or high dosage. A variable may alternatively be quantitative (continuous or discrete).

 

 

Center of a circle: the point that all points in the circle are equidistant from

 

 

Central limit theorem: The means of a relatively large (>30) number of random samples from any population (not necessarily a normal distribution) will be approximately normally distributed with the population mean being their mean and variance being the (population variance / n). This approximation will improve as the sample size (the number of samples) increases.

 

 

Chord of a circle: a segment whose endpoints are on a circle

 

 

Circle: the set of points on a plane at a certain distance (radius) from a certain point (center); a polygon with infinite sides

 

 

Circumference: the perimeter of a circle

 

 

Coefficient of variation: It is a measure of spread for a set of data. It is a measure of variation in relation to the mean. Calculated as standard deviation divided by the mean (x100).

 

 

Coefficient: The numerical factor when a term has a variable (Ex. In the expression 3x + 2y = 16, 2 and 3 are coefficients.)

 

 

Collinear: in the same line

 

 

Commutative Property: A property of addition or multiplication in which the sum or product stays the same when the order of the addends or factors is changed (i.e., a + b = b + a and ab = ba).

 

 

Commutative Property: If two numbers are added or multiplied, the operations can be done in any order.   Ex.  4 x 5 = 5 x 4

 

 

Compass: a drawing tool used to draw circles at different radii

 

 

Complementary angles: 2 angles whose measures, when added together, equal 90 degrees; see supplementary angles

 

 

Composite number: Any integer that is not a prime number  (evenly divisible by numbers other than one and itself)

 

 

Congruent figures: two figures where one is the image of the other under a reflection or composite of reflections; written A B

 

 

Congruent: equilateral, equal, exactly the same (size, shape, etc.)

 

 

Consecutive sides: sides of a polygon that share an endpoint

 

 

Consecutive vertices: endpoints of a single side of a polygon

 

 

Consecutive: Following one another in an uninterrupted order  (Ex.  6, 7, 8, and 9 are consecutive numbers.)

 

 

Constant: In an algebraic expression, the number without the variable  (Ex. In the expression 2x + 5, 5 is the constant.)

 

 

Construction: a precise way of drawing which allows only 2 tools: the straightedge and the compass

 

 

Coordinate geometry: the study of geometrically representing ordered pairs of numbers

 

 

Coordinate plane: a plane in which every point is identified with exactly 1 number and vice versa; a two-dimensional graph

 

 

Coordinate system/Cartesian Plane: A method of locating points in the plane or in space by means of numbers (A point in a plane can be located by its distances from both a horizontal and a vertical line called the axes.  The horizontal line is called the x-axis.  The vertical line is called the y-axis.  The pairs of numbers are called ordered pairs.  The first number, called the x-coordinate, designates the distance along the horizontal axis.  The second number, called the y-coordinate, designates the distance along the vertical axis.  The point at which the two axes intersect has the coordinates (0,0) and is called the origin.)

 

 

Coordinate: a number that identifies (or helps to identify) a point on a number line (or on a plane, or in space)

 

 

Coordinate: A set of numbers that locates the position of a point usually represented by (x, y) values

 

 

Coplanar: within the same plane

 

 

Corresponding angles: any pair of angles in similar locations with respect to a transversal

 

 

 

 D

 

Data: Information gathered by observation, questioning, or measurement

 

 

Degree: unit used to measure angles

 

 

Descriptive statistics: Summary of available data. Examples are male-to-female ratio in a group; numbers of patients in each subgroup; the mean weight of male and female students in a class, etc. Only when the distribution is symmetric, mean and standard deviation can be used. Otherwise (as in survival data), mean and percentiles/range should be used to describe the data.

 

 

Diagonal: a segment in a polygon whose endpoints are 2 nonconsecutive vertices

 

 

Diameter of a circle (or sphere): the segment whose endpoints are points on a circle (or sphere) that contains the center of the circle as its midpoint; the length of that segment

 

 

Discrete variable: A variable of countable number of integer outcomes.

 

 

Distance between 2 parallel lines: the length of a perpendicular segment between them

 

 

Distance: the distance between points A and B is written as AB

 

 

Distributive Property: A property that relates two operations on numbers, usually multiplication and addition, or multiplication and subtraction       Ex.  a(x + y) = ax + ay

 

 

Distributive Property: A property which establishes a relationship between multiplication and addition such that multiplication distributes across the addition [i.e., a(b+c) = ab + ac].

 

 

Divisibility (rules of): Special tests to determine if a particular integer is a factor of a given number, (e.g., a number is divisible by 10 if it ends in a 0).

 

 

Drawing: a freehand picture using any tool; see construction

 

 

 E

 

Edge: a segment that helps to make up a face

 

 

Empty set: null set

 

 

Equation: A mathematical sentence containing an equal sign

 

 

Equation: A mathematical sentence of equality between two expressions (e.g., N + 50 = 75 or 75 = N + 50 means that N + 50 must have the same value as 75).

 

 

Equiangular: having angles of the same measure

 

 

Equidistant: the same distance from something

 

 

Equilateral triangle: a triangle whose sides are equal in length

 

 

Equilateral: equal in length

 

 

Equivalent: Numbers or expressions that have the same value.

 

 

Estimation: The process of finding a number close to an exact amount.

Ex.   = 3 x 3 or 9

 

 

Exponent: A number showing how many times the base is used as a factor

 

 

Exponent: A number which is placed to the right of and above another number (base). The value of the exponent determines how many times the base is used as a factor (e.g., 34 = 3 x 3 x 3 x3; {3 is the base and is used as a factor 4 times} the exponent is 4).

 

 

Exponential form: A way of writing numbers using bases and exponents [e.g., 425 = (4 x 102) + (2 x 101) + (5 x 100)].

 

 

Expression: A mathematical statement that does not contain an equal sign

 

 

Exterior angles: angles outside of two lines cut by a transversal; see interior angles

 

 

 

 F

 

Factor: Any numbers multiplied by another number to produce a product

 

 

Factor: The numbers or terms multiplied in an expression.

 

 

Factoring: A method used to solve a quadratic equation that requires using the zero product property (Factoring is a process of rewriting a number or expression as product of two or more numbers or expressions.)

 

 

Formula: An equation that states a fact or rule (e.g., A= w).

 

 

Formulas: Specific equations giving rules for relationships between quantities

 

 

Function Notation: To write a rule in function notation, you use the symbol f(x) in place of y. (Ex.  f(x) = 3x – 8 is in functional notation.)

 

 

Function: A relation in which each member of the domain is paired with one, and only one, member of the range

 

 

 

G

 

 

Gambler’s ruin: A classical topic in probability theory. It is a game of chance related to a series of Bernoulli trials. There are variations of the game theory associated with problems of the random walk and sequential sampling.

 

 

Game theory: The theory of contests between two or more players under specified sets of rules. The statistical aspect is that the game proceeds under a chance scheme such as throwing a die.

 

 

Given: information assumed to be true in a proof

 

 

H

 

Horizontal line: a line whose slope is zero

 

 

Hypotenuse: the side opposite the right angle in a right triangle

 

 

I

 

Included angle: the angle made by two sides of a polygon

 

 

Included side: the side between two angles in a polygon

 

 

Inclusive or: one or the other, or both; and/or

 

 

Inequality:  A mathematical statement that one quantity is less than (<) or greater than (>) another

 

 

Inequality: A mathematical sentence in which the value of the expressions on either side of the relation symbol are unequal. Relation symbols include >, <, , , or (e.g., x < y, 7 > 3, n 4).

 

 

Integer: A set of whole numbers and its opposites (i.e. …..-3, -2, -1, 0, 1, 2, 3…)

 

 

Integers: The set of whole numbers and their opposites

 

 

Intercept: In linear regression, the intercept is the mean value of the response variable when the explanatory variable takes the value of zero (the value of y when x=0).

 

 

Interior angles: angles between two lines cut by a transversal; see exterior angles

 

 

Interior of a circle: the set of points whose distance from the center of the circle is less than that of the radius

 

 

Interior of an angle: the convex set formed by an angle that measures less than 180 degrees; see exterior of an angle

 

 

Interquartile range (IQR): IQR is a measure of spread and is the counterpart of the standard deviation for skewed distributions. IQR is the distance between the upper and lower quartiles (Q­U-QL).

 

 

Intersecting planes: planes that share a line

 

 

Interval variable (equivalent to continuous variable): A quantitative variable measured on a scale with constant intervals (like days, milliliters, kilograms, miles so that equal-sized differences on different parts of the scale are equivalent) where the zero point and unit of measurement are arbitrary. When temperature is measured on two scales, Fahrenheit and Centigrade, the zero points in these two scales do not correspond, and a 10% increase in Fahrenheit (from 500 to 550) is not a 10% increase in the corresponding Centigrade scale (10o to 12.8o = 2.8%); these two measurements cannot be mixed or compared. For estimation of correlation coefficients, data should be interval type.

 

 

Inverse operations: Two operations that “undo” each other (e.g., addition and subtraction).

 

 

Irrational numbers: Real numbers that cannot be expressed in the form a/b (a fraction) where a and b are integers

 

 

Isosceles triangle: a triangle with two sides of equal length

 

 

 

L

 

Large sample effect: In large samples, even small or trivial differences can become statistically significant.

 

 

Likelihood: The probability of a set of observations given the value of some parameter or set of parameters.

 

 

Line graph: A means of displaying statistical information by connecting graphs of ordered pairs to show changes in quantities

 

 

Line perpendicular to a plane: a line perpendicular to every line in the plane that it intersects (or any one of them)

 

 

Line: a two-dimensional object that has no endpoints and continues on forever in a plane; formed of infinite points; the 3 orientations that lines may have are horizontal, vertical, oblique, and skew lines; written

 

 

Linear function: A function that has a constant rate of change and can be modeled by a straight line

 

 

Linear function: A function with no exponents other than one and with no products of the variables (e.g., y=x+4, y= -4, and 3x-4y = 1/2 are linear functions); in a rectangular coordinate system, the graph of a linear function is a line.

 

 

Linear pair: 2 supplementary adjacent angles whose non-common sides form a line.

 

 

Lines: A set of points (x, y) that satisfy the equation ax + by + c = 0 where a and b are not both zero

 

 

Literal equation: An equation involving two or more variables

 

 

 

M

 

Mean (or average): A measure of location for a batch of data values; the sum of all data values divided by the number of elements in the distribution. Its accompanying measure of spread is usually the standard deviation. Unlike the median and the mode, it is not appropriate to use the mean to characterize a skewed distribution (see also standard deviation)

 

 

Measure: the amount of openness in an angle

 

 

Measures of central tendency: These are parameters that characterize an entire distribution. These include mode, median and mean.

 

 

Median: Another measure of location just like the mean. The mean is the value that divides the frequency distribution into half when all data values are listed in order. It is insensitive to small numbers of extreme scores in a distribution. Therefore, it is the preferred measure of central tendency for a skewed distribution

 

 

Midpoint: the point M of where AM = AB

 

 

Mode: The observed value that occurs with the greatest frequency. The mode is not influenced by small numbers of extreme values.

 

 

Monomial: An expression that is a number, a variable, or a product of a number and variable   (Ex. 7, x and 8xy are all monomials.)

 

 

Multiple: The product of a whole number and any other whole number.

 

 

Multiplicative inverse: Two numbers are multiplicative inverses of each other if their product is 1 (e.g., since 4 x 1/4 = 1, 1/4 and 4 are multiplicative inverses).

 

 

 

N

 

Natural Numbers: One of the numbers 1, 2, 3, 4… also called counting numbers

 

 

Null model: A model in which all parameters except the intercept are 0. It is also called the intercept-only model. The null model in linear regression is that the slope is 0, so that the predicted value of Y is the mean of Y for all values of X.

 

 

Number sense: The ability of the learner to make logical connections between new information and previously acquired knowledge to understand the meanings, relationships, and magnitudes of numbers and common measurements

 

 

Number Theory: Concepts of numbers such as prime, composite, squares, factors and multiples

 

 

 

 

O

Obtuse angle: an angle whose measure is greater than 90 but less than 180 degrees; see acute angle

 

 

Odds: The odds of a success are defined as the ratio of the probability of a success to the probability of a failure ( ). If a team has a probability of 0.6 of winning the championship, the odds for winning is = 3:2.

 

 

Ordinal numbers: Numbers used to express order (e.g., 1st, 2nd, 3rd).

 

 

Outcome (response, dependent) variable: The observed variable, which is shown on y axis. A statistical model shows this as a function of predictor variable(s).

 

 

Outlier: Extreme observations that are well separated from the remainder of the data. In regression analysis, not all outlying values will have an influence on the fitted function. Those outlying with regard to their X values (high leverage), and those with Y values that are not consistent with the regression relation for the other values (high residual) are expected to be influential. The test the influence of such values, the Cook statistics is used.

 

 

Overlapping triangles: triangles that share a side or angle

 

 

 

P

 

Parallel lines: two or more coplanar lines that have no points in common or are identical (eg, the same line)

 

 

Parallel planes: planes that have no points in common

 

 

Parallelogram: a quadrilateral with both pairs of opposite sides parallel

 

 

Parameter: A numerical characteristic of a population specifying a distribution model (such as normal or Poisson distribution). This may be the mean, variance, degrees of freedom, the probability of a success in a binomial distribution, etc.

 

 

Percent: A special ratio that compares a number to 100 and uses the % sign (e.g., 1/2 = 50% and 2/3 = 66 2/3%).

 

 

Perfect Square: Trinomial: Any trinomial in the form a² + 2ab + b²

 

 

Perimeter of a polygon: the sum of the lengths of the sides of the polygon

 

 

Perpendicular bisector: the bisector of a segment perpendicular to it

 

 

Perpendicular lines: 2 segments, rays, or lines that form a 90 degree angle

 

 

Perpendicular planes: planes in which any two intersecting lines, one in each plane, form a right angle

 

 

Pi: written π ( for those of you who can’t read math tags yet); the ratio C/D where C is the circumference and D is the diameter of a circle; 3.14159265359

 

 

Place Value: The value of a digit as determined by its position in a number (e.g., in the number “11” the one is worth either 10 or 1, depending on the position).

 

 

Plane figure: a set of points that are on a plane

 

 

Plane geometry: the study of two-dimensional figures in a plane

 

 

Plane: a two-dimensional group of points that goes on infinitely in all directions; made up of infinite lines

 

 

Point slope form: A linear equation of a non-vertical line written as y – y1 = m(x – x1)

 

 

Point: a zero-dimensional figure; while usually left undefined, has four main representations – the dot, the node, the location, and the ordered pair of numbers

 

 

Polygon: a union of 3 or more segments where each segment intersects 2 other segments, one at each endpoint; “many sided”; see reflex polygon

 

 

Polynomial: In algebra, an expression consisting of two or more terms  (Ex.  x² -2xy + y²)

 

 

Population: The population is the universe of all the objects from which a sample could be drawn for an experiment.

 

 

Postulate: a statement assumed to be true without proof; see theorem

 

 

Power: A number expressed using an exponent (e.g., the number 53 is read five to the third power or five cubed).

 

 

Powers: Numbers that can be expressed using exponents

 

 

Precision: The smallest place value to which an approximate number or measurement is expressed (e.g., if pi is represented as 3.14, then its precision is .01).

 

 

Prime number: A whole number greater than 1 that can only be divided evenly by itself and 1 (e.g., 17).

 

 

Prime Numbers: A whole number greater than one having exactly two distinct factors, one and itself

 

 

Probability: The ratio of the number of likely outcomes to the number of possible outcomes.

 

 

Proof: a sequence of justified conclusions used to prove the validity of an if-then statement

 

 

Properties of operations: Mathematical principals that are always true (e.g., commutative, associative, distributive, inverses).

 

 

Proportion: An equation of the form a/b=c/d which states that the two ratios are equivalent.

 

 

Proportion: An equation that states that two ratios are equal

 

 

Protractor: a tool used to measure angles

 

 

Prove: the goal of a proof

 

 

Pythagorean Theorem: In a right triangle, the sum of the squares of the length of the legs is equal to the square of the length of the hypotenuse.    Ex.  a² + b² = c²

 

 

Q

 

Quadrilateral: a four-sided polygon; see rhombus, parallelogram, square, rectangle, trapezoid, isosceles trapezoid, kite

 

 

Qualitative: Qualitative (categorical) variables define different categories or classes of an attribute. Examples are gender, blood groups or disease states. A qualitative (categorical) variable may be nominal or ordinal. When there are only two categories, it is termed binary (like sex, dead or alive).

 

 

Quantitative: Quantitative variables are variables for which a numeric value representing an amount is measured. They may be discrete (for example, taking values of integers) or continuous (such as weight, height, blood pressure). If a quantitative variable is categorized, it becomes an ordinal variable.

 

 

R

 

Radii: plural form of radius

 

 

Radius: the segment whose endpoints are any point on a circle or sphere and its center; the length of that segment

 

 

Random sampling: A method of selecting a sample from a target population or study base using simple or systematic random methods. In random sampling, each subject in the target population has equal chance of being selected to the sample. Sampling is a crucially important point in selection of controls for a case-control study. By randomization, systematic effects are turned into error (term), and there is an expected balancing out effect: known and unknown factors that might influence the outcome are assigned equally to the comparison groups. One disadvantage of randomization is generation of a potentially large error term.

 

 

Rate: A ratio comparing two different units (e.g., miles per hour).

 

 

Ratio variable: A quantitative variable that has a zero point as its origin (like 0 cm = 0 inch) so that ratios between values are meaningfully defined. Unlike the

 

 

Ratio: A comparison of two numbers, represented in one of the following ways: 2 to 5, 2 out of 5, 2:5, or 2/5

 

 

Ratio: A comparison of two whole numbers by division.

 

 

Rational number: A real number that can be written as a quotient of two integers a/b, where b does not equal 0; a repeating or terminating decimal, integer, fraction, or whole number.

 

 

Rational Numbers: A number in the form of an a/b, where a and b are integers and b is not equal to zero

 

 

Ray: a one-dimensional figure that consists of one endpoint A, one point B, all of the points on , and all points for which B is between them and A; written

 

 

Real number: Any number that is either rational or irrational.

 

 

Rectangle: a quadrilateral whose angles are all right angles

 

 

Region: the union of a figure and its interior

 

 

Regular polygon: a convex polygon whose angles and sides are all congruent

 

 

Representations: Different ways to show the same mathematical concepts (i.e., ¼, .25, 25%)

 

 

Rhombus: a parallelogram with four equilateral sides

 

 

Right angle: an angle whose measure is 90 degrees

 

 

Right triangle: a triangle that has a 90 degree angle

 

 Roman Numbers List: Check Roman Numbers List

 

 

 

 

S

 

Scientific Notation: A means of expressing a number as a product of a number between one and ten and a power of ten    Ex. 1100 = 1.1 x 10³

 

 

Scientific notation: Representation of a number as the product of a number between 1 and 10 and a power of 10; used especially for very small or very large numbers (e.g., 6,900,000 = 6.9 x 106 or .00069 = 6.9 x10-4).

 

 

Segment: the set of points consisting of two distinct points and all inbetween them; written

 

 

Simultaneous (Systems) Equations: Pair of equations of the first degree upon which two different conditions are put on the same variables at the same time (Ex.  Find two numbers whose sum is 7 and whose difference is 1.  x + y = 7 and x – y = 1.)

 

 

Skew lines: non-coplanar lines that don’t intersect

 

 

Skewness: The degree of (lack of) asymmetry about a central value of a distribution. A distribution with many small values and few large values is positively (right) skewed (long tail in the distribution curve or stem plot is to the right); the opposite (left tail) is negatively (left) skewed. The measures of location median, mid-interquartile range (midQ) and midrange decrease in this order for a left-skewed distribution.

 

 

Slope: The ratio of the vertical change to the horizontal change

 

 

Slope-intercept form: A linear equation in the form y = mx + b, where m is the slope of the graph of the equation and b is the y-intercept

 

 

Standard deviation: Like variance, the standard deviation (SD) is a measure of spread (scatter) of a set of data. Unlike variance, which is expressed in squared units of measurement, the SD is expressed in the same units as the measurements of the original data. It is calculated from the deviations between each data value and the sample mean. It is the square root of the variance.

 

 

Standard form of a linear equation: The form of a linear equation Ax + By = C where A, B, and C are real numbers and A and C are not both zero      (Ex.  6x – y = 12)

 

 

Standard form of a polynomial: The form of a polynomial in which the degree of the terms decreases from left to right (descending order)

 

 

Straight angle: an angle whose measure is 180 degrees, forming a line with its sides

 

 

Straightedge, unmarked: just how it sounds, an unmarked tool used to draw straight lines

 

 

Supplementary angles: 2 angles whose measures, when added together, equal 180 degrees

 

 

Surface: the boundary of a 3-D figure

 

 

 

 

 

T

 

Theorem: important mathematical statements which can be proven by postulates, definitions, and/or previously proved theorems

 

 

Three-dimensional: having length, width, and thickness (i.e., space)

 

 

Transversal: a line that intersects 2 others

 

 

Triangle: a polygon with three sides; see equilateral triangle, isosceles triangle, right triangle, scalene triangle

 

 

Trinomial: An expression containing three terms connected by a plus or minus sign (Ex.  5x² + 3x – 6)

 

 

Two-dimensional: having both width and length, but no thickness

 

 

U

 

Units of measure: Inches, meters, pounds, grams, etc.

 

 

V

 

Variable: A letter or symbol which represents one or more number or value

 

 

Variable: Some characteristic that varies among experimental units (subjects) or from time to time. A variable may be quantitative or categorical. A quantitative variable is either discrete (assigning meaningful numerical values to observations: number of children, dosage in mg) or continuous (such as height, weight, temperature, blood pressure; also called interval variable). A categorical variable is either nominal (assigning observations to categories: gender, treatment, disease subtype, groups) or ordinal (ranked variables: low, median, high dosage). Conventionally, a random variable is shown by a capital letter, and the data values it takes by lower case letters.

 

 

Variance: The major measure of variability for a data set. To calculate the variance, all data values, their mean, and the number of data values are required. It is expressed in the squared unit of measurement. Its square root is the standard deviation.

 

 

Vertex angle: the angle formed by the equilateral sides of an isosceles triangle

 

 

Vertex of an angle: the common endpoint of the two rays

 

 

Vertical angles: 2 angles that share a common vertex and whose sides form 2 lines

 

 

Vertical line: a line that goes straight up and down, and whose slope is defined as infinite or undefined

 

 

 

 

 

 

 

 

W

 

Whole numbers: The numbers in the set {0, 1, 2, 3 …}. The set of natural numbers and zero

 

 

 

 

 

X

 

X-axis: The horizontal axis of a coordinate plane

 

 

X-coordinate: The location on the x-axis of a point on the coordinate plane

 

 

X-intercept: The x-coordinate of the point where a line crosses the x-axis

 

 

 

 

Y

 

Y-axis: The vertical axis of a coordinate plane

 

 

Y-coordinate: The location on the y-axis of a point on the coordinate plane

 

 

Y-intercept: The y-coordinate of the point where the line crosses the y-axis

 

 

 

 

Z

 

Zero angle: an angle whose measure is 0. In a zero angle, both the initial and terminal sides are the same.

 

 

Zero-dimensional: having no dimension; a point