- 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
Upper triangular systems are solved in reverse order Xn to Xl.
Change of basis matrix M.
The old basis vectors v j are combinations L mij Wi of the new basis vectors. The coordinates of CI VI + ... + cnvn = dl wI + ... + dn Wn are related by d = M c. (For n = 2 set VI = mll WI +m21 W2, V2 = m12WI +m22w2.)
Characteristic equation det(A - AI) = O.
The n roots are the eigenvalues of 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).
z = a - ib for any complex number z = a + ib. Then zz = Iz12.
When random variables Xi have mean = average value = 0, their covariances "'£ ij are the averages of XiX j. With means Xi, the matrix :E = mean of (x - x) (x - x) T is positive (semi)definite; :E is diagonal if the Xi are independent.
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.
Hessenberg matrix H.
Triangular matrix with one extra nonzero adjacent diagonal.
Kronecker product (tensor product) A ® B.
Blocks aij B, eigenvalues Ap(A)Aq(B).
Normal equation AT Ax = ATb.
Gives the least squares solution to Ax = b if A has full rank n (independent columns). The equation says that (columns of A)·(b - Ax) = o.
Nullspace matrix N.
The columns of N are the n - r special solutions to As = O.
Orthogonal matrix Q.
Square matrix with orthonormal columns, so QT = Q-l. Preserves length and angles, IIQxll = IIxll and (QX)T(Qy) = xTy. AlllAI = 1, with orthogonal eigenvectors. Examples: Rotation, reflection, permutation.
Every v in V is orthogonal to every w in W.
Pivot columns of A.
Columns that contain pivots after row reduction. These are not combinations of earlier columns. The pivot columns are a basis for the column space.
Pseudoinverse A+ (Moore-Penrose inverse).
The n by m matrix that "inverts" A from column space back to row space, with N(A+) = N(AT). A+ A and AA+ are the projection matrices onto the row space and column space. Rank(A +) = rank(A).
Row picture of Ax = b.
Each equation gives a plane in Rn; the planes intersect at x.
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.
Sum V + W of subs paces.
Space of all (v in V) + (w in W). Direct sum: V n W = to}.
Volume of box.
The rows (or the columns) of A generate a box with volume I det(A) I.
Stretch and shift the time axis to create Wjk(t) = woo(2j t - k).