Algebra Vocabulary List

A ƒ Absolute Value Function – The absolute value of a real number x, x is ⎧ x if x ≥ 0 x =⎨ ⎩− x if x < 0 ƒ ƒ ƒ ƒ Algebra Lab Gear – a set of manipulatives that are designed to represent polynomial expressions. The set includes representations for positive/negative 1, 5, 25, x, 5x, y, 5y, xy, x2, y2, x3, y3, x2y, xy2. The manipulatives can be used to model addition, subtraction, multiplication, division, and factoring of polynomials. They can also be used to model how to solve linear equations. Algebra Tiles – a set of manipulatives that are designed for modeling algebraic expressions visually. Each tile is a geometric model of a term. The set includes representations for positive/negative 1, x, and x2. The manipulatives can be used to model addition, subtraction, multiplication, division, and factoring of polynomials. They can also be used to model how to solve linear equations. Algebraic Expression – a number, variable, or combination of the two connected by some mathematical operation like addition, subtraction, multiplication, division, exponents and/or roots. Area Under the Curve – suppose the curve y=f(x) lies above the x axis for all x in [a, b]. The area under the curve is the area of the region bounded by the curve, the “x” axis and the b lines x=a and x=b. It equals ∫ f ( x)dx. a • Arithmetic Sequence (arithmetic progression) – A sequence of numbers in which the difference of two consecutive terms is the same. A sequence with a general term an +1 = an + d or an = a1 + (n − 1)d is called an arithmetic sequence. Example: let d=2 and a1 = 1 , then 1,3,5,7,… forms an arithmetic sequence with first term equal to 1 and common difference(difference between any two consecutive terms) equal to 2. ƒ Arithmetic Series – the indicated sum of the terms of an arithmetic sequence. Example of finite arithmetic series: 1 + 3 + 5 + 7 + 9 (Note this is the sum of a finite arithmetic sequence whose first term is 1 and common difference is 2). In general, the sum of a finite arithmetic n series is ∑ a i = n ( a1 + a n ) / 2 i =1 B ƒ Binomial – an expression consisting of two terms, such as 2x + 5y or 7x2 + 4 . C ƒ Coefficient – the numerical part of a term, usually written before the literal part, as 2 in 2x or 2(x + y). Most commonly used in algebra for the constant factors, as distinguished from the variables. ƒ Coefficient Matrix (matrix of the coefficients) – the matrix of coefficients of the variables in a system of equations written in standard form. For example: the coefficient matrix for ⎡ 2 − 3⎤ 2x – 3y = 8 and 4x + 5y = 2 is denoted by ⎢ ⎥. ⎣4 5 ⎦ ƒ ƒ ƒ ƒ Compressed Graph (vertical shrink) – a shrink in which a plane figure is distorted vertically. It’s a transformation in which all distances on the coordinate plane are shortened by multiplying all y coordinates of a graph by a common factor less than 1. Constant – a symbol representing a value that doesn’t change. Continuous Curve – can be depicted as, “path of a continuously moving point”. A line or curve that extends without a break or abrupt changes. Cramer’s Rules – a rule using determinants to express the solution of a system of linear algebraic equations for which the number of equations is equal to the number of variables. e f bd For example: To solve x and y from ax + by = e; cx + dy = f ; x = ;y= ab cd where ƒ e f ac , ab cd ab = ad − bc . cd Cubic Function – a polynomial function of degree 3, usually written in the form y = ax3 + bx2 + cx + d, where a, b, c and d are constants. ƒ D ƒ Degree of a Monomial – the degree of a term in one variable is the exponent of that variable; the degree of a term in several variables is equal to the sum of the exponents of its variables. For example, the degree of 4x2 is 2 and the degree of 4x2y3z2is 7. ƒ ƒ Degree of a Polynomial – the degree of the monomial of largest degree belonging to that polynomial. For example, the degree of a polynomial, 4x5 + 6x2 + 8 is 5. Determinant – is a special set of mathematical operations associated with a square array. The result of the operation is a scalar value. The determinant below has two rows and two columns and is called a second-order determinant. a b c d A second-order determinant is evaluated as follows. a b = ad − bc c d Notice that the value of the determinant is found by calculating the difference of the products of the two diagonals. a b bc ad - bc c d ad Value of a Second-Order Determinant: ƒ ƒ ƒ Difference of Squares – a difference of two squares can be represented in an expression of the form a2 – b2 and factors into the form (a + b)(a – b). Direct Variation – a linear function of the form y = cx, where c is the constant of variation; c ≠ 0. We say that y is directly proportional to x, i.e. y varies directly as x varies. If x is doubled, tripled or halved, then y is also doubled, tripled, or halved. If x increases one unit, then y increases c units. Domain of a Function – The set of all possible input values of a function. Given a real valued function f ( x) = o For more info: 1 , its domain is the set of all real numbers excluding 0. x E ƒ Equation – A statement asserting the equality of two expressions that are separated into left and right sides and joined by an equal sign. ƒ Exponential Function – an equation of the form f(x) = a · bx + k where a ≠ 0, b > 0, b ≠1 and x is any real number , is called an exponential function with base b. ƒ F ƒ FOIL method – an application of the distributive property used to multiply two binomials. The product of the two binomials is found by multiplying the First, Outer, Inner, and Last terms. ƒ Function – a set of ordered pairs such that no two ordered pairs have the same first member. A relation, such that each element of a set (the domain) is associated with a unique element of another (possibly the same) set (the co-domain not to be confused with the range). ƒ Function Notation – function notation uses f(x) (or g(x), h(x), etc.), instead of y, to represent the dependent variable. ƒ G ƒ Geometric Sequence (geometric progression) – is a sequence of numbers in which each term is obtained by multiplying the preceding term by the same number (common ratio). The following is a geometric progression: 1, 2, 4, 8, 16, 32… The common ratio for this geometric progression is 2. ƒ Geometric Series – The indicated sum of the terms of a geometric sequence. The geometric series corresponding to the geometric sequence: 1, 2, 4, 8, 16, 32… is 1 + 2 + 4 + 8 + 16 + 32 +… ƒ ƒ Graphs – a pictorial representation of some mathematical relationship. It can be a point on a number line, which is a graph of a real number. ƒ H ƒ Horizontal Asymptote – if there exists a number c such that the curve f(x) approaches c as x approaches ∞ or f(x) approaches c as x approaches −∞ , then the line y=c is called a horizontal asymptote of the curve f(x). o For more info: ƒ http://archives.math.utk.edu/visual.calculus/1/horizontal.5/ I ƒ ƒ ƒ Identity Function – is a function in the form f(x) = x. More generally, an identity function is one which does not change the domain values at all. Inequality – An inequality is a statement with the symbol <, , >, or between numerical or variable expressions. Infinite Series – An infinite series is an infinite, ordered set of terms combined together by 1 1 1 the addition operator. For example: 1 + + + + ...... 2 3 4 ƒ ƒ Interval on a Real Number Line – is the set containing all numbers between two given numbers (the end points of the interval) including one, both, or neither end point. Inverse Function – if f is a one to one and onto function from a set X to a set Y, then the correspondence that goes back from Y to X is also a function and is known as the inverse function. For the definition of onto and one to one functions please look under “O”. ƒ ƒ ƒ k Inverse Variation – A variation stated in the form y = , where k is the constant of x variation. In this equation the values of y get smaller as the vales of x get greater. It is said that x and y are inversely proportional. Iteration – repetition of a sequence of instructions. Iteration is characterized by a set of initial conditions, an iterative step and a termination condition. For example, the set of Fibonacci numbers is generated by beginning with 1, 1, and using the iterative process of summing the two previous terms to determine all subsequent terms. The set of Fibonacci numbers is {1, 1, 2, 3, 5, 8, 13. . .} L Limit (Limit of a function in one variable) – a limit is the value of the function as the variable approaches a particular point. For example the limit of the function x as x approaches 4 is 2. The limit of 1/ n as n approaches infinity is 0. Linear Function – a function whose graph is a straight line. A linear function of x can be written in the form f(x) = mx + b, where m and b are constants. Logarithmic Function – The logarithmic function f(x) = logbx is the inverse of the exponential function f(x) = bx, where b > 0 and b ≠ 1. A function defined by an expression of the form log f(x). ƒ M ƒ Matrix – a rectangular array of variables or constants in horizontal rows and vertical columns, usually enclosed in brackets. ƒ Monomial – an expression that can be a constant, a variable, or a product of a constant and one or more variable. Each of the following is a monomial. 5 (a constant) 3z (a product of a constant and one variable) x (a variable) 6xyz (a product of a constant and more than one variable) N ƒ ƒ 1 Natural Exponent (e) – e ≈ 2.718281828… e is the limit of (1 + ) n as n approaches infinity. n Non-Linear Function - A function whose graph is not a straight line. Example: Polynomials of degree two or higher, exponential function, sine, cosine functions etc. ƒ O ƒ One-to-One Function – a function f is said to be one to one (injective) if and only if f(x) = f(y) implies x = y. i.e. no two distinct elements in the domain correspond to the same element in the Range. ƒ P ƒ Parabola – The general shape of the graph of a quadratic function. The set of all points in a plane that are the same distance from a given point called the focus and a given line called the directrix. ƒ Parent Function – the basic function for a family of functions. For instance, y = x2 is the parent function of the family of quadratic functions. ƒ Polynomial – Sum and/or difference of terms: example: 3x – 2 and 4x2 -5x + 3 A polynomial with two terms is a binomial. A polynomial with three terms is a trinomial ƒ Polynomial Function – a function of the form P ( x) = an x n + an −1 x n −1 + ...a1 x + a0 for all real x, where the coefficients are real numbers and n a non negative integer. If an ≠ 0 , P(x) is called a real polynomial of degree n. ƒ Proportion – the statement of equality of two ratios; an equation stating that two ratios are equal. ƒ Q ƒ Quadratic Function – a polynomial function of degree 2, and in the form f(x) = ax2 + bx + c. ƒ R Range (range of a function) – The set of possible values which a function's output can be. Given the function {(1, 5), (2, 10), (13, 15), (4, 20)} its range is {5, 10, 15, 20}. ƒ Rate of Change – the ratio of the change in one quantity to a corresponding unit change in another quantity. ƒ ƒ ƒ p ( x) , where q( x) p(x) and q(x) are polynomial functions and q(x) ≠ 0. (The domain of f consists of all real numbers x such that the denominator q(x) is not equal to 0.) Rational Function – division of two polynomial functions in the form f ( x) = ƒ Recursive Formula – a recursive formula has two parts: the value(s) of the first term(s), and a recursion equation that shows how to find each term from the term(s) before it. ƒ Recursive Sequence – a recursive sequence is an ordered list of numbers defined by a starting value and a rule, applying the rule again to the previous value, and repeating this process. ƒ ƒ Relation – A relation is any subset of a Cartesian product. For instance, a subset of A × B , called a "binary relation from A to B," is a collection of ordered pairs (a, b) with first components from A and second components from B, and, in particular, a subset of A × A is called a "relation on A." ƒ Root – a solution of an equation. ƒ Roots of the Equation – a number which, when substituted for the variable in the equation satisfies the equation. For example: 2 is a root for the equation x2 −4 = 0 , but 3 is not. ƒ S ƒ Sequence of Numbers – An ordered arrangement of numbers. We denote a sequence as 1 1 1 ∞ an n =1 where its nth term is an . For example: consider the sequence 1, , , ..... it can also 2 3 4 ∞ be expressed as 1 . n n =1 ƒ ƒ ƒ ƒ Slope – the ratio of rise to run for a line in the coordinate plane. The slope of a line described by f(x) = mx + b is m. Slope of the Tangent Line – the slope of the line that is tangent to the function graph at a certain point (c, f(c)). (The line that passes through the point (c, f(c)) with slope f ' (c) is called the tangent line at the point (c, f(c)). Stretched Graph – A transformation in which all distances on the coordinate plane are lengthened by multiplying either all x-coordinates (horizontal dilation) or all y-coordinates (vertical dilation) of a graph by a common factor greater than 1. Symmetry about the X-axis – if for any point (x, y) on a graph, the point (x, -y) is also on the graph, then the graph is said to be symmetric with respect to the X-axis. Also, if the ƒ ƒ Symmetry about the Y-axis – if for any point (x, y) on a graph, the point (-x, y) is also on the graph, then the graph is said to be symmetric with respect to the Y-axis. Also, if the equation of the curve is unaltered when x is replaced by –x .i.e. f ( x, y) = f (− x, y) System of Equations – two or more equations in two or more variables considered together or simultaneously. The equations in the system may or may not have a common solution. ƒ T ƒ Table of Values (Table) – a systematic listing of results already worked out. ƒ ƒ ƒ Translation – a transformation in which a figure is moved from one location to another on the coordinate plane without changing its size, shape, or orientation. Trinomial – a polynomial with three unlike terms. For example, x2 – 3x + 2. Two-Color Counters – a disk-shaped manipulative that is generally white on one side and red on the other side. These counters are often used for introducing integer concepts. The white side represents a positive one value, and the red side represents a negative one value. V ƒ Variable –A variable is a symbol on whose value a function, polynomial, etc., depends. For example, the variables in the function f(x,y) are x and y. A function having a single variable is said to be univariate, one having two variables is said to be bivariate, and one having two or more variables is said to be multivariate. ƒ Vertical Asymptote – The line x=c is a vertical asymptote for a function f, if any of the following condition holds: 1. f approaches ∞ or − ∞ as x approaches c. 2. f approaches ∞ or − ∞ as x approaches c from the left. 3. f approaches ∞ or − ∞ as x approaches c from the right. ƒ X ƒ X-intercept – the x-coordinate of the point at which a graph crosses the x-axis. o Y ƒ Y-intercept - the y-coordinate of the point at which a graph crosses the y-axis. ƒ Z ƒ Zero (of a function) – for any function f(x), if f(a) = 0, then a is a zero of the function. The value(s) of x for which the value of the function is zero. The real zeros of a function are the x-intercepts of its graph in the coordinate plane.