Skip to main content

Math 382-0: Kursobjekt

Appendix E Examples

0.1 Sets

Example 0.1.7

0.2 Functions

Example 0.2.2
Example 0.2.3 Arithmetic operations as functions
Example 0.2.8 Role of domain and codomain in injectivity and surjectivity

0.4 Logic

Example 0.4.3
Example 0.4.7 Modeling “Every positive number has a square-root”
Example 0.4.10 The limit does not exist

0.5 Proof techniques

Example 0.5.3 Proof: invertible is equivalent to bijective
Example 0.5.4 Proof by contradiction
Example 0.5.8 Weak induction
Example 0.5.10 Strong induction

1.1 Complex arithmetic

Example 1.1.7 Complex arithmetic
Example 1.1.12 Real square roots
Example 1.1.16 Inverses and quotients

1.2 Geometry of complex numbers

Example 1.2.6 Circles and discs
Example 1.2.15 Polar form
Example 1.2.18 Polar form arithmetic

1.3 De Moivre’s formula

Example 1.3.2 De Moivre’s formula
Example 1.3.3 Double-angle formulas
Example 1.3.4 Triple-angle formula
Example 1.3.6 Cube-roots of \(8i\)
Example 1.3.13 Factoring \(f(x)=x^6-1\)

1.4 Topology of \(\C\)

Example 1.4.4 Open sets
Example 1.4.9 Open, closed, neither
Example 1.4.12 Boundary

1.5 Sequences and series

Example 1.5.6 Limit of sequence
Example 1.5.7 Divergent sequence
Example 1.5.8 Sequence with infinite limit
Example 1.5.11 Geometric series

1.6 Complex functions

Example 1.6.5 Real and imaginary parts
Example 1.6.10 Squaring transformation
Example 1.6.13 Exponential transformation

1.7 Logarithmic and trigonometric functions

Example 1.7.5 Logarithm
Example 1.7.6 Invalid identity
Example 1.7.8 Powers
Example 1.7.9 \(n\)-th roots

1.8 Limits of functions and continuity

Example 1.8.2 Limit points
Example 1.8.5 No limit
Example 1.8.7 Limit of power function

1.9 Complex differentiation

Example 1.9.6 Elementary examples
Example 1.9.9 Polynomials

1.10 Cauchy-Riemann equations

Example 1.10.3 Cauchy-Riemann verification
Example 1.10.4 Complex conjugation
Example 1.10.7 Exponential and trigonometric functions
Example 1.10.15 Derivative of \(\Log\)
Example 1.10.16 Reciprocal function
Example 1.10.17 Derivative of power function

1.11 Branches and harmonic functions

Example 1.11.4 Relating \(\alpha\)-cut branches
Example 1.11.5 \(\Log_\alpha(z)\) is holomorphic
Example 1.11.7 Branches of cube-root function
Example 1.11.10 Harmonic conjugates

1.12 Complex paths

Example 1.12.3 Parametrized curves
Example 1.12.7 Tangent vectors
Example 1.12.11 Complex-valued function integration

1.13 Complex line integrals

Example 1.13.4 Classic line integral
Example 1.13.6 Line integral: FTC

1.14 Cauchy-Goursat theorem

Example 1.14.13 Star-shaped and elementary regions
Example 1.14.21 Principle of deformation

1.15 Cauchy integral formula

Example 1.15.3 Cauchy Integral formula
Example 1.15.5 Cauchy integral formula: cosine

1.16 Generalized Cauchy integral formula

Example 1.16.4 Generalized Cauchy integral formula

1.17 Complex power series

Example 1.17.3 Power series representation
Example 1.17.8 Expansions and radii of convergence
Example 1.17.11 Differentiating power series
Example 1.17.12 Power series for \(\Log\)

1.19 Analytic continuation

Example 1.19.3 Order of a zero
Example 1.19.5 Order of \(f\) at \(z_0\)
Example 1.19.14 Real analytic functions

1.20 Laurent series

Example 1.20.4 Laurent series expansion
Example 1.20.6 Different Laurent series
Example 1.20.8 Truncated Laurent series
Example 1.20.10 Laurent series of rational function

1.21 Cauchy residue theorem

Example 1.21.5 Cauchy residue theorem
Example 1.21.6 Cauchy residue theorem: two singularities
Example 1.21.8 Residue at simple pole

1.22 Poles and residue computation

Example 1.22.3 Singularity classification
Example 1.22.8 Residue computation

1.23 Definite integrals

Example 1.23.5 Trig integral over \([0,2\pi]\)
Example 1.23.7 Rational function on real line
Example 1.23.8 Trig integral over real line
Example 1.23.10 Logarithmic improper integral
Example 1.23.11 Sinc function
Example 1.23.13 Integral of power function

1.24 Winding number

Example 1.24.2 Winding numbers of circles

1.25 Rouché’s theorem and open mapping theorem

Example 1.25.2 Roots of polynomials

1.27 Conformal maps

Example 1.27.7 Conformal map: squaring function
Example 1.27.12 Möbius transformation