Class Diary for M247, Fall 2015, Jochen Denzler


Wed Aug 19: Intro material. Examples of multi-variable functions; different notation cultures distinguished. Points and their coordinates.
Thu Aug 20: Vectors; geometric and algebraic aspects; dot product and angle measurement. spherical and cylindrical coordinates introduced.
Fri Aug 21: Cauchy Schwarz inequality explained and proved. Vector valued functions of a single variable (example of a spiral staircase). Hwk 1-5 due Wed
Mon Aug 24: clarification hwk 4; vector valued functions of a single variable: path of a particle, velocity (vs speed), acceleration; parametrized curve and arclength
Wed Aug 26: Help with hwk 5 (extended till tomorrow); example of cycloid and its arclength. Hwk 6-9 due Mon.
Thu Aug 27: Example: evolvent of cycloid (ie unrolling twine from a cycloid). Unit tangent vector; its deriv is orthogonal to the tangent vector itself. Definition of curvature
Fri Aug 28: graph y=f(x) and its curvature. Intro to cross product (geometric definition).
Mon Aug 31: Properties of cross product and formula for it. Hwk 10-13 due Fri.
Wed Sep 02: Curvature in terms of cross product; Discussion of returned homework 6-8.
Thu Sep 03: multi-variable functions; their graphs and level sets. Definition of a limit explained.
Fri Sep 04: >Hwk 14-18 due next Fri. Class discussion mainly guidance through these hwk problems.
Mon Sep 07: LABOR DAY
Wed Sep 09: some Q re hwk. Refinement of def. of limit, when function is not the entire R^n. Open sets
Thu Sep 10: Open sets; Boundary; closed sets. Partial derivatives of a function (that we assume to be defined on an open set). Directional derivative.
Fri Sep 11: Intro to total derivative; tangent planes to a graph; what is a matrix?
Mon Sep 14: Discussion of old and new homework Hwk 19-22 due Thu if possible Tangent lines from directional derivatives may or may not assemble into a tangent plane. Matrix multiplication defined.
Wed Sep 16: Hwk deadline extended till Fri More on matrix multiplication. Differentiability (and total derivative) in terms of tangential planes and by a limit reminiscent of single variable difference quotients.
Thu Sep 17: Total derivative: an example calculation for working with the definition. Continuity of partial derivatives on an open set guarantees total differentiability.
Fri Sep 18: Total derivative also for vector valuaed functions; its relation with directional derivatives.
Mon Sep 21: Hwk discussion
Wed Sep 23: EXAM 1 ; New Hwk #22-27 due next Wed
Thu Sep 24: Gradient; chain rule just started
Fri Sep 25: Chain rule
Mon Sep 28: Applications of chain rule
Wed Sep 30: Exam return and discussion
Thu Oct 01: 2nd partial derivatives; Hessian
Fri Oct 02: The Hessian. Two theorems about minimax: existence, and 1st derivative test.
Mon Oct 05: 2nd derivative test. 2nd order directional derivatives are v^T H v.
Wed Oct 07: Positive definiteness and Hurwitz test (determinants up to 2x2) Hwk 32-34 due next Wed
Thu Oct 08: 3x3 determinants (for the sake of Hurwitz test for positive definiteness); Gershgorin test. An example of a minimax problem in practice
Fri Oct 09: Example of minimax problem finished
Mon Oct 12: Constrained minimax problems; an example solved by elimination; Lagrange multipliers started
Wed Oct 14: Lagrange multipliers finished, and example.
Thu Oct 15: FALL BREAK
Fri Oct 16: FALL BREAK
Mon Oct 19: Hwk 35-39 due Mon. Q&A. Implicit function theorem in 2 variables.
Wed Oct 21: Intro to multi-variable integration.
Thu Oct 22: Riemann-Integral of piecewise cont functions defined. Its evaluation by repeated integrals. Example where inner integration limits are variable.
Fri Oct 23: Example finished. Area element in polar coordinates.
Mon Oct 26: Transformation formula in 2 dim; New Hwk 40-42 due Mon
Wed Oct 28: Example for transformation formula in 3d: torus coordinates
Thu Oct 29: EXAM 2
Fri Oct 30: Applications: Moment of inertia; center of mass. Started: integration of a scalar function over a curve
Mon Nov 02: integration of a scalar function over a curve; e.g., Center of mass of a cardioid.
Wed Nov 04: Integrals over curves: vector functions; work New Hwk 43-47 due next Wed
Thu Nov 05: Curve integrals over vector fields, and path independence.
Fri Nov 06: (Substituted by AF) Conservative vector fields
Mon Nov 09: Parametrized surfaces and area.
Wed Nov 11: center of mass of a surface, briefly. Flux integrals: definition and interpretation
Thu Nov 12: A calc' exaple of flux integrals. Flux integrals over closed surfaces can be converted into volume integrals: divergence of a vector field defined. [Result stated, no explanation yet.]
Fri Nov 13: Statement of Gauss' theorem without proof yet. Green's theorem for `very nice' domains (type 3 in Marsden-Tromba).
Mon Nov 16: decomposition of domains into type 3 pieces; Green's thm in general; application to area inside a curve.
Wed Nov 18: Curl of a vector field. Stokes' theorem stated and explained.
Thu Nov 19: EXAM 3
Fri Nov 20: Stokes' theorem proved.
Mon Nov 23: Return to conservative vector fields; domains with `holes' (not simply connected). 2D Gauss theorem as a consequence from Green.
Wed Nov 25: Fun material - not exam relevant. If you leave early: have a safe trip. If you travel after class: have a safe trip, too.
Thu Nov 26: THANKSGIVING
Fri Nov 27: THANKSGIVING BREAK
Mon Nov 30:
Wed Dec 02: STUDY DAY
Tue Dec 08: FINAL EXAM 02:45-04:45 (scheduled by university policy), see exam schedule by class.

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