- Chapter 1: Equations and Inequalities
- Chapter 1.1: Graphs and Graphing Utilities
- Chapter 1.2: Linear Equations and Rational Equations
- Chapter 1.3: Models and Applications
- Chapter 1.4: Complex Numbers
- Chapter 1.5: Quadratic Equations
- Chapter 1.6: Other Types of Equations
- Chapter 1.7: Linear Inequalities and Absolute Value Inequalities
- Chapter 2: Functions and Graphs
- Chapter 2.1: Basics of Functions and Their Graphs
- Chapter 2.2: More on Functions and Their Graphs
- Chapter 2.3: Linear Functions and Slope
- Chapter 2.4: More on Slope
- Chapter 2.5: Transformations of Functions
- Chapter 2.6: Combinations of Functions; Composite Functions
- Chapter 2.7: Inverse Functions
- Chapter 2.8: Distance and Midpoint Formulas; Circles
- Chapter 3: Polynomial and Rational Functions
- Chapter 3.1: Quadratic Functions
- Chapter 3.2: Polynomial Functions and Their Graphs
- Chapter 3.3: Dividing Polynomials; Remainder and Factor Theorems
- Chapter 3.4: Zeros of Polynomial Functions
- Chapter 3.5: Rational Functions and Their Graphs
- Chapter 3.6: Polynomial and Rational Inequalities
- Chapter 3.7: Modeling Using Variation
- Chapter 4: Exponential and Logarithmic Functions
- Chapter 4.1: Exponential Functions
- Chapter 4.2: Logarithmic Functions
- Chapter 4.3: Properties of Logarithms
- Chapter 4.4: Exponential and Logarithmic Equations
- Chapter 4.5: Exponential Growth and Decay; Modeling Data
- Chapter 5: Systems of Equations and Inequalities
- Chapter 5.1: Systems of Linear Equations in Two Variables
- Chapter 5.2: Systems of Linear Equations in Three Variables
- Chapter 5.3: Partial Fractions
- Chapter 5.4: Systems of Nonlinear Equations in Two Variables
- Chapter 5.5: Systems of Inequalities
- Chapter 5.6: Linear Programming
- Chapter 6: Matrices and Determinants
- Chapter 6.1: Matrix Solutions to Linear Systems
- Chapter 6.2: Inconsistent and Dependent Systems and Their Applications
- Chapter 6.3: Matrix Operations and Their Applications
- Chapter 6.4: Multiplicative Inverses of Matrices and Matrix Equations
- Chapter 6.5: Determinants and Cramers Rule
- Chapter 7: Conic Sections
- Chapter 7.1: The Ellipse
- Chapter 7.2: The Hyperbola
- Chapter 7.3: The Parabola
- Chapter 8: Sequences, Induction, and Probability
- Chapter 8.1: Sequences and Summation Notation
- Chapter 8.2: Arithmetic Sequences
- Chapter 8.3: Geometric Sequences and Series
- Chapter 8.4: Mathematical Induction
- Chapter 8.5: The Binomial Theorem
- Chapter 8.6: Counting Principles, Permutations, and Combinations
- Chapter 8.7: Probability
- Chapter P: Prerequisites: Fundamental Concepts of Algebra
- Chapter P.1: Algebraic Expressions, Mathematical Models, and Real Numbers
- Chapter P.2: Exponents and Scientific Notation
- Chapter P.3: Radicals and Rational Exponents
- Chapter P.4: Polynomials
- Chapter P.5: Factoring Polynomials
- Chapter P.6: Rational Expressions
College Algebra 7th Edition - Solutions by Chapter
Full solutions for College Algebra | 7th Edition
Augmented matrix [A b].
Ax = b is solvable when b is in the column space of A; then [A b] has the same rank as A. Elimination on [A b] keeps equations correct.
Column picture of Ax = b.
The vector b becomes a combination of the columns of A. The system is solvable only when b is in the column space C (A).
Put CI, ... ,Cn in row n and put n - 1 ones just above the main diagonal. Then det(A - AI) = ±(CI + c2A + C3A 2 + .•. + cnA n-l - An).
Eigenvalue A and eigenvector x.
Ax = AX with x#-O so det(A - AI) = o.
Elimination matrix = Elementary matrix Eij.
The identity matrix with an extra -eij in the i, j entry (i #- j). Then Eij A subtracts eij times row j of A from row i.
A sequence of row operations that reduces A to an upper triangular U or to the reduced form R = rref(A). Then A = LU with multipliers eO in L, or P A = L U with row exchanges in P, or E A = R with an invertible E.
Exponential eAt = I + At + (At)2 12! + ...
has derivative AeAt; eAt u(O) solves u' = Au.
Fast Fourier Transform (FFT).
A factorization of the Fourier matrix Fn into e = log2 n matrices Si times a permutation. Each Si needs only nl2 multiplications, so Fnx and Fn-1c can be computed with ne/2 multiplications. Revolutionary.
Free columns of A.
Columns without pivots; these are combinations of earlier columns.
The nullspace N (A) and row space C (AT) are orthogonal complements in Rn(perpendicular from Ax = 0 with dimensions rand n - r). Applied to AT, the column space C(A) is the orthogonal complement of N(AT) in Rm.
Hessenberg matrix H.
Triangular matrix with one extra nonzero adjacent diagonal.
Inverse matrix A-I.
Square matrix with A-I A = I and AA-l = I. No inverse if det A = 0 and rank(A) < n and Ax = 0 for a nonzero vector x. The inverses of AB and AT are B-1 A-I and (A-I)T. Cofactor formula (A-l)ij = Cji! detA.
Linear combination cv + d w or L C jV j.
Vector addition and scalar multiplication.
Markov matrix M.
All mij > 0 and each column sum is 1. Largest eigenvalue A = 1. If mij > 0, the columns of Mk approach the steady state eigenvector M s = s > O.
Nilpotent matrix N.
Some power of N is the zero matrix, N k = o. The only eigenvalue is A = 0 (repeated n times). Examples: triangular matrices with zero diagonal.
Projection p = a(aTblaTa) onto the line through a.
P = aaT laTa has rank l.
Simplex method for linear programming.
The minimum cost vector x * is found by moving from comer to lower cost comer along the edges of the feasible set (where the constraints Ax = b and x > 0 are satisfied). Minimum cost at a comer!
Singular Value Decomposition
(SVD) A = U:E VT = (orthogonal) ( diag)( orthogonal) First r columns of U and V are orthonormal bases of C (A) and C (AT), AVi = O'iUi with singular value O'i > O. Last columns are orthonormal bases of nullspaces.
Transpose matrix AT.
Entries AL = Ajj. AT is n by In, AT A is square, symmetric, positive semidefinite. The transposes of AB and A-I are BT AT and (AT)-I.
Vandermonde matrix V.
V c = b gives coefficients of p(x) = Co + ... + Cn_IXn- 1 with P(Xi) = bi. Vij = (Xi)j-I and det V = product of (Xk - Xi) for k > i.