- Chapter 1: First-Order Differential Equations
- Chapter 10: Systems of Linear Differential Equations
- Chapter 11: Vector Differential Calculus
- Chapter 12: Vector Integral Calculus
- Chapter 13: Fourier Series
- Chapter 14: Fourier Series
- Chapter 15: Special Functions and Eigenfunction Expansions
- Chapter 16: Wave Motion on an Interval
- Chapter 17: The Heat Equation
- Chapter 18: The Potential Equation
- Chapter 19: Complex Numbers and Functions
- Chapter 2: Linear Second-Order Equations
- Chapter 20: Complex Integration
- Chapter 21: Complex Integration
- Chapter 22: The Residue Theorem
- Chapter 23: Conformal Mappings and Applications
- Chapter 3: The Laplace Transform
- Chapter 4: Series Solutions
- Chapter 5: Approximation of Solutions
- Chapter 6: Vectors and Vector Spaces
- Chapter 7: Matrices and Linear Systems
- Chapter 8: Determinants
- Chapter 9: Eigenvalues, Diagonalization, and Special Matrices
Advanced Engineering Mathematics 7th Edition - Solutions by Chapter
Full solutions for Advanced Engineering Mathematics | 7th Edition
Upper triangular systems are solved in reverse order Xn to Xl.
Basis for V.
Independent vectors VI, ... , v d whose linear combinations give each vector in V as v = CIVI + ... + CdVd. V has many bases, each basis gives unique c's. A vector space has many bases!
Characteristic equation det(A - AI) = O.
The n roots are the eigenvalues of A.
S. Permutation with S21 = 1, S32 = 1, ... , finally SIn = 1. Its eigenvalues are the nth roots e2lrik/n of 1; eigenvectors are columns of the Fourier matrix F.
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.
Hankel matrix H.
Constant along each antidiagonal; hij depends on i + j.
Kronecker product (tensor product) A ® B.
Blocks aij B, eigenvalues Ap(A)Aq(B).
Krylov subspace Kj(A, b).
The subspace spanned by b, Ab, ... , Aj-Ib. Numerical methods approximate A -I b by x j with residual b - Ax j in this subspace. A good basis for K j requires only multiplication by A at each step.
Least squares solution X.
The vector x that minimizes the error lie 112 solves AT Ax = ATb. Then e = b - Ax is orthogonal to all columns of A.
Left inverse A+.
If A has full column rank n, then A+ = (AT A)-I AT has A+ A = In.
Matrix multiplication AB.
The i, j entry of AB is (row i of A)·(column j of B) = L aikbkj. By columns: Column j of AB = A times column j of B. By rows: row i of A multiplies B. Columns times rows: AB = sum of (column k)(row k). All these equivalent definitions come from the rule that A B times x equals A times B x .
Nullspace matrix N.
The columns of N are the n - r special solutions to As = O.
Particular solution x p.
Any solution to Ax = b; often x p has free variables = o.
Permutation matrix P.
There are n! orders of 1, ... , n. The n! P 's have the rows of I in those orders. P A puts the rows of A in the same order. P is even or odd (det P = 1 or -1) based on the number of row exchanges to reach I.
Polar decomposition A = Q H.
Orthogonal Q times positive (semi)definite H.
Skew-symmetric matrix K.
The transpose is -K, since Kij = -Kji. Eigenvalues are pure imaginary, eigenvectors are orthogonal, eKt is an orthogonal matrix.
Solvable system Ax = b.
The right side b is in the column space of A.
Combinations of VI, ... ,Vm fill the space. The columns of A span C (A)!
Symmetric matrix A.
The transpose is AT = A, and aU = a ji. A-I is also symmetric.
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.