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🍓AP Pre-Calculus Unit 4 Vocabulary

123 essential vocabulary terms and definitions for Unit 4 – Functions Involving Parameters, Vectors, and Matrices

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🍓Unit 4 – Functions Involving Parameters, Vectors, and Matrices
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🍓Unit 4 – Functions Involving Parameters, Vectors, and Matrices

4.10 Matrices

TermDefinition
columnThe vertical lines of elements in a matrix.
dot productA scalar quantity obtained by multiplying the magnitudes of two vectors and the cosine of the angle between them; equals zero when vectors are perpendicular.
matrixA rectangular array of numbers arranged in rows and columns that represents a linear transformation.
matrix productThe product of two matrices that represents the composition of their corresponding linear transformations.
rowThe horizontal lines of elements in a matrix.

4.1 Parametric Functions

TermDefinition
domainThe set of all possible input values for which a function is defined.
parameterAn independent variable (often denoted t) used to express the coordinates of points on a curve in parametric form.
parametric equationsA pair of equations that express x and y coordinates as functions of a parameter, typically written as x(t) and y(t).
parametric functionA function that expresses the coordinates of a point as functions of a parameter, typically time t, written as f(t) = (x(t), y(t)).

4.11 The Inverse and Determinant of a Matrix

TermDefinition
2 × 2 matrixA square matrix with 2 rows and 2 columns.
column vectorVectors represented as columns in a matrix; when two column vectors form a 2×2 matrix, the absolute value of the determinant gives the area of the parallelogram they span.
determinantA scalar value calculated from a square matrix that determines whether the matrix is invertible; for a 2×2 matrix [a b; c d], the determinant equals ad - bc.
identity matrixA square matrix with 1s on the main diagonal (from top left to bottom right) and 0s everywhere else.
invertibilityThe property of a square matrix that has an inverse; a matrix is invertible if and only if its determinant is nonzero.
matrix inverseA matrix that, when multiplied by the original matrix, produces the identity matrix; a square matrix has an inverse if and only if its determinant is nonzero.
parallel vectorsVectors that have the same or opposite direction, resulting from scalar multiplication of a vector by a constant.
parallelogramA quadrilateral formed by two vectors; the area of the parallelogram spanned by two vectors equals the absolute value of the determinant of the matrix formed by those vectors.
row vectorVectors represented as rows in a matrix; when two row vectors form a 2×2 matrix, the absolute value of the determinant gives the area of the parallelogram they span.
square matrixA matrix with the same number of rows and columns; only square matrices can have determinants and inverses.

4.12 Linear Transformations and Matrices

TermDefinition
input vectorThe vector that is mapped or transformed by a linear transformation.
linear transformationA function that maps vectors to vectors while preserving vector addition and scalar multiplication, represented by a matrix.
matrix multiplicationThe operation of multiplying a transformation matrix by a vector or matrix to produce output vectors.
output vectorThe resulting vector produced by applying a linear transformation to an input vector.
ℝ²The two-dimensional real vector space consisting of all ordered pairs of real numbers.
transformation matrixA 2 × 2 matrix A that represents a linear transformation, where L(v) = Av for vectors v in ℝ².
zero vectorA vector with components ⟨0, 0⟩ that occurs when the tail and head are at the same point.

4.13 Matrices as Functions

TermDefinition
composition of functionsA function operation where one function is applied to the output of another function, written as (f ∘ g)(x) = f(g(x)).
composition of linear transformationsThe result of applying one linear transformation followed by another linear transformation.
determinantA scalar value calculated from a square matrix that determines whether the matrix is invertible; for a 2×2 matrix [a b; c d], the determinant equals ad - bc.
dilationA linear transformation that scales regions by a constant factor, with the magnitude determined by the absolute value of the determinant.
inverse transformationsTwo linear transformations that are inverses if their composition maps any vector to itself, effectively undoing each other's effects.
linear transformationA function that maps vectors to vectors while preserving vector addition and scalar multiplication, represented by a matrix.
matrixA rectangular array of numbers arranged in rows and columns that represents a linear transformation.
matrix inverseA matrix that, when multiplied by the original matrix, produces the identity matrix; a square matrix has an inverse if and only if its determinant is nonzero.
matrix productThe product of two matrices that represents the composition of their corresponding linear transformations.
rotationA linear transformation that rotates every vector by a fixed angle about the origin without changing its length.
unit vectorA vector with a magnitude of 1, often used to indicate direction.
vectorA mathematical object with both magnitude and direction, represented as an ordered pair of components in ℝ².

4.14 Matrices Modeling Contexts

TermDefinition
discrete intervalsSeparate, distinct time periods or steps used to measure changes in a system, rather than continuous time.
future statesThe predicted conditions or distributions of a system at subsequent time steps using matrix multiplication.
matrix inverseA matrix that, when multiplied by the original matrix, produces the identity matrix; a square matrix has an inverse if and only if its determinant is nonzero.
matrix modelsMathematical representations using matrices to represent transitions or changes between different states in a system.
past statesThe predicted conditions or distributions of a system at previous time steps using the inverse of a transition matrix.
percent changeThe relative change in a quantity expressed as a percentage, which is related to the growth factor in an exponential model.
repeated multiplicationA process where an initial value is multiplied by the same proportion multiple times, which can be modeled using logarithmic functions.
state vectorA column vector that represents the distribution or values across different states at a particular point in time.
steady stateA distribution between states that remains unchanged from one step to the next after repeated matrix multiplication.
transition matrixA matrix that models the probabilities or rates of moving from one state to another in a system.
transitions between statesChanges or movements from one condition or situation to another in a system being modeled.

4.2 Parametric Functions Modeling Planar Motion

TermDefinition
horizontal extremaThe maximum and minimum x-coordinates reached by a particle during its motion, found by identifying extrema of x(t).
parametric functionA function that expresses the coordinates of a point as functions of a parameter, typically time t, written as f(t) = (x(t), y(t)).
particle motionThe path and position of a particle as it moves through space over time, modeled using parametric equations.
planar motionThe movement of a particle or object in a two-dimensional plane.
real zeroA real number value that makes a polynomial function equal to zero, corresponding to an x-intercept on the graph.
vertical extremaThe maximum and minimum y-coordinates reached by a particle during its motion, found by identifying extrema of y(t).
x-interceptThe point where a graph crosses or touches the x-axis, occurring at (a, 0) when a is a real zero of the function.
y-interceptsThe points where the particle's path crosses the y-axis, corresponding to the real zeros of x(t).

4.3 Parametric Functions and Rates of Change

TermDefinition
average rate of changeThe change in the output of a function divided by the change in the input over a specified interval, calculated as (f(b) - f(a))/(b - a) for the interval [a, b].
direction of motionThe path direction a particle follows in the plane, determined by whether x(t) and y(t) are increasing or decreasing.
parametric planar motion functionA function that describes the motion of a particle in a plane using a parameter (typically time) to define both x and y coordinates independently.
parametrizationA representation of a curve using a pair of functions (x(t), y(t)) where both x and y are expressed in terms of a parameter t.
rate of changeThe measure of how quickly a function's output changes relative to changes in its input.
slope of the graphThe ratio of the average rate of change of y to the average rate of change of x between two points on a parametric curve.

4.4 Parametrically Defined Circles and Lines

TermDefinition
circular pathA curve traced in the plane that forms a circle, defined by parametric equations.
counterclockwise revolutionMotion around a circle in the counterclockwise direction, completing a full 360-degree rotation.
line segmentThe portion of a line between two endpoints, characterized by a starting point and an ending point.
linear pathA straight line segment connecting two points in the coordinate plane.
parametric functionA function that expresses the coordinates of a point as functions of a parameter, typically time t, written as f(t) = (x(t), y(t)).
parametricallyExpressed using parametric equations where x and y coordinates are defined as functions of a parameter, typically time (t).
rate of changeThe measure of how quickly a function's output changes relative to changes in its input.
transformationChanges applied to a parent function such as translations, reflections, stretches, or compressions.
unit circleA circle with radius 1 centered at the origin, used to define trigonometric functions where a point on the circle has coordinates (cos θ, sin θ).

4.5 Implicitly Defined Functions

TermDefinition
equation involving two variablesA mathematical statement with an equals sign containing two different variables, which can describe one or more functions or be graphed in a coordinate plane.
implicitly defined functionA function defined by an equation relating x and y, rather than explicitly solving for y in terms of x.
ordered pairsPoints on a graph represented as (x, y) coordinates that satisfy the equation of a function.
rate of changeThe measure of how quickly a function's output changes relative to changes in its input.
solutions to an equationThe ordered pairs of values that satisfy an equation involving two variables and can be plotted as points on a graph.

4.6 Conic Sections

TermDefinition
asymptoteLines that a graph approaches but never reaches, indicating behavior at infinity or at points of discontinuity.
circleA special case of an ellipse where the horizontal and vertical radii are equal (a = b).
conic sectionsCurves formed by the intersection of a plane with a cone, including parabolas, ellipses, circles, and hyperbolas.
ellipseA conic section formed when a plane intersects a cone at an angle, or the set of points where the sum of distances to two foci is constant.
horizontal radiusThe distance from the center of an ellipse to its edge along the horizontal axis, represented by the value a.
hyperbolaA conic section formed when a plane intersects both nappes of a cone, or the set of points where the difference of distances to two foci is constant.
parabolaA conic section formed when a plane intersects a cone parallel to its side, or the set of points equidistant from a focus and directrix.
vertexThe point (h, k) that represents the center or turning point of a parabola.
vertical radiusThe distance from the center of an ellipse to its edge along the vertical axis, represented by the value b.

4.7 Parametrization of Implicitly Defined Functions

TermDefinition
conic sectionsCurves formed by the intersection of a plane with a cone, including parabolas, ellipses, circles, and hyperbolas.
domainThe set of all possible input values for which a function is defined.
ellipseA conic section formed when a plane intersects a cone at an angle, or the set of points where the sum of distances to two foci is constant.
hyperbolaA conic section formed when a plane intersects both nappes of a cone, or the set of points where the difference of distances to two foci is constant.
implicitly defined functionA function defined by an equation relating x and y, rather than explicitly solving for y in terms of x.
inverse functionA function that reverses the mapping of another function, such that if f(x) = y, then f⁻¹(y) = x.
invertible functionA function that has an inverse function; a one-to-one function where each output corresponds to exactly one input.
parabolaA conic section formed when a plane intersects a cone parallel to its side, or the set of points equidistant from a focus and directrix.
parameterAn independent variable (often denoted t) used to express the coordinates of points on a curve in parametric form.
parametric equationsA pair of equations that express x and y coordinates as functions of a parameter, typically written as x(t) and y(t).
parametrizationA representation of a curve using a pair of functions (x(t), y(t)) where both x and y are expressed in terms of a parameter t.
trigonometric parametrizationA method of representing curves using trigonometric functions (such as sine, cosine, secant, and tangent) as the parametric equations.

4.8 Vectors

TermDefinition
angle measureThe input value in a polar function that represents the direction from the positive x-axis, typically measured in radians or degrees.
componentsThe horizontal (a) and vertical (b) values of a vector, where a = x₂ - x₁ and b = y₂ - y₁.
directed line segmentA line segment with a specified direction from a starting point to an ending point.
directionThe orientation of a vector, which is parallel to the line segment from the origin to the point with coordinates (a, b).
dot productA scalar quantity obtained by multiplying the magnitudes of two vectors and the cosine of the angle between them; equals zero when vectors are perpendicular.
headThe ending point or tip of a vector.
Law of CosinesA relationship used to find side lengths or angle measures in a triangle when given other side lengths and angles.
Law of SinesA relationship stating that the ratio of a side length to the sine of its opposite angle is constant for all sides and angles in a triangle.
magnitudeThe length of a vector, calculated as the square root of the sum of the squares of its components.
parallel vectorsVectors that have the same or opposite direction, resulting from scalar multiplication of a vector by a constant.
perpendicularTwo vectors are perpendicular when the angle between them is 90 degrees, indicated by a dot product of zero.
scalar multiplicationThe multiplication of a constant (scalar) by a vector, resulting in a new vector whose components are each multiplied by that constant.
standard basis vectorsThe unit vectors →i = ⟨1, 0⟩ and →j = ⟨0, 1⟩ that point in the positive x and y directions, respectively, in ℝ².
tailThe starting point or beginning of a vector.
unit vectorA vector with a magnitude of 1, often used to indicate direction.
vectorA mathematical object with both magnitude and direction, represented as an ordered pair of components in ℝ².
vector additionThe process of combining two or more vectors to produce a resultant vector.
vector sumThe addition of two vectors by adding their corresponding components to produce a new vector.
zero vectorA vector with components ⟨0, 0⟩ that occurs when the tail and head are at the same point.

4.9 Vector-Valued Functions

TermDefinition
parametric functionA function that expresses the coordinates of a point as functions of a parameter, typically time t, written as f(t) = (x(t), y(t)).
planar motionThe movement of a particle or object in a two-dimensional plane.
position vectorA vector that represents the location of a particle relative to the origin, with magnitude equal to the distance from the origin.
speedThe magnitude of the velocity vector, representing the rate at which a particle is moving regardless of direction.
vector-valued functionA function that outputs vectors, typically expressed as p(t) = ⟨x(t), y(t)⟩ or p(t) = x(t)i + y(t)j, where each input t produces a vector output.
velocity vectorA vector-valued function v(t) = ⟨x'(t), y'(t)⟩ that represents the rate of change of position with respect to time, indicating both direction and speed of motion.