Midterm II Review for Math 421, Fall 2009
Technical terms you must know.
You must be able to give a
careful, complete and accurate of these terms. You must also know examples
of all of these terms (and their negations or combinations if that makes
sense).
- an open or closed set
- a limit point of a set
- the closure of a set
- a compact set
- an open cover of a set
- a connected set
- a functional limit (both ε-δ and topological forms)
- a continuous function
- a uniformly continuous function
- the derivative of a function, a differentiable function
Theorems/Results/Axioms/Examples you must know.
This means you must
be able to state them and to give examples of them being true and examples
of how the conclusion is false if individual hypothesese are dropped (for
the theorems), and discuss why (i.e., prove, albeit with a reduced
standard of rigor) the claimed properties hold true (for the examples).
- results relating different definitions of "closed set"
- results on finite&arbitrary unions&intersections of
open&closed sets
- the Heine-Borel Theorem
- results giving different characterizations of compactness
- examples of functions with interesting discontinuity sets:
- Df is a single point
- Df is an open set
- Df is a closed set
- Dirichlet's function
- the modified Dirichlet function
- Thomae's function
- the Divergence Criterion for Functional Limits
- the theorem giving four different characterizations of continuity
- theorems on continuous functions preserving compactness and
connectedness (also the EVT and IVT versions)
- a theorem on [uniformly] continuous functions on compact sets
- theorems relating continuity and differentiability
- the Interior Extremum Theorem
- Darboux's Theorem
- Rolle's Theorem
- the Mean Value Theorem
- L'Hospital's Rule
- a continuous function which is non-differentiable at a point, or is
non-differentiable everywhere
Theorems you should be able to prove during an in-class midterm:
- Heine-Borel
- the theorems on continuous functions preserving compactness and
connectedness
- differentiability implies continuity
- the Interior Extremum Theorem
- Rolle's Theorem
- Some simple propositions/theorems from the book, like:
- Theorem 3.2.13
- Theorem 4.3.9
- Corollary 5.3.3
- maybe a simple textbook exercise...