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Appendix C Notation

The following table defines the notation used in this book. Page numbers or references refer to the first appearance of each symbol.
Symbol Description Location
x(t)=f(t,x),x(0)=x0 first-order initial value problem Subsection 1.1.1
dPdt=k(1PN)P logistic population model Subsection 1.1.2
mx+bx+kx=0 simple damped harmonic oscillator Subsection 1.1.3
dydx=M(x)N(y) separable differential equation Subsection 1.2.1
dxdt+p(t)x=q(t) first-order linear differential equation Subsection 1.5.2
dxdt=fλ(x) one-parameter family Subsection 1.7.2
x(t) vector-valued function Subsection 2.2.2
dxdt=f(t,x),x(t0)=x0 vector form of a system Subsection 2.3.2
dxdt=f(x),dydt=g(x,y) partially coupled system Subsection 2.4.1
dxdt=Ax matrix notation for a system Section 3.1
A1 inverse of a matrix A Subsection 3.1.1
det(A) determinant of A Subsection 3.1.1
xT matrix transpose Subsection 3.1.2
det(AλI)=λ2(a+d)λ+(adbc) characteristic polynomial Subsection 3.1.3
tr(A) trace of A Exercises 3.1.6
I identity matrix Exercises 3.1.6
eiβt=cosβt+isinβt Euler’s formula Subsection 3.4.1
xRe real part of a complex number or vector Subsection 3.4.1
xIm imaginary part of a complex number or vector Subsection 3.4.1
λ complex conjugate Subsection 3.4.3
eA matrix exponential Subsection 3.9.1
eA matrix exponential Subsection 3.9.1
a(t)x+b(t)x+c(t)x=g(t) second-order linear differential equation Section 4.1
p(λ)=det(AλI)=λ2+baλ+ca characteristic polynomial Subsection 4.1.2
W[f,g](t) Wronskian Exercises 4.2.7
ω0 natural frequency Subsection 4.4.1
ω driving frequency Subsection 4.4.1
ω mean frequency Subsection 4.4.2
δ half difference Subsection 4.4.2
H(λ) transfer function Subsection 4.4.3
G(ω) gain Subsection 4.4.3
J Jacobian matrix Subsection 5.1.1
H Hamiltonian function Subsection 5.2.2
L(f)(s) Laplace transform Subsection 6.1.1
ua(t)=u(ta) Heaviside function Example 6.1.5
L1(F(s))(t) inverse Laplace transform Subsection 6.1.3
Γ(x) gamma function Exercises 6.1.7
δ Dirac delta function Subsection 6.3.1
fg convolution product Subsection 6.4.1