PEI Math 521K study materials
PEI Math 521K study resources

PEI Math 521K study plan

PEI Math 521K · Give each week a clear focus.

8 weeks · About 7 hours per week

Week 1

Real Number System and Elementary Logic & Proof Technique and Rigorous Argumentation

  • Write out the field and order axioms for R from memory, then prove three consequences (uniqueness of 0 and 1, cancellation laws, sign rules for products of negatives) without consulting notes.

  • Prove by induction that 1+2+...+n = n(n+1)/2 and that 2^n > n for all n ≥ 1, stating the base case and inductive step explicitly each time.

  • Translate five English statements into quantified logic with correct quantifier order, and negate each one mechanically (swap ∀/∃, negate the predicate).

  • Distinguish valid proof patterns (direct, contrapositive, contradiction, induction) by matching each of eight short claims to the technique that actually works, and explain why the others fail.

  • Prove the Archimedean property and the density of Q in R using only completeness (supremum) as a starting point.

Your checkpoint

A handwritten or typeset proof portfolio of 10 complete proofs (axioms, induction, quantifier negation, Archimedean property, density of Q) with each step justified by a named axiom, definition, or prior result.

Week 2

Real Number System and Elementary Logic & Sequences, Series, and Limits

  • Prove that every nonempty subset of R bounded above has a least upper bound, and use it to derive the nested interval property and the Bolzano–Weierstrass theorem for sequences.

  • State the ε-N definition of convergence and use it to prove limits of at least four sequences from scratch, including one where you must choose N as an explicit function of ε.

  • Prove that convergent sequences are bounded and that limits are unique, writing the triangle-inequality estimates explicitly.

  • Classify monotone sequences using the monotone convergence theorem, and apply it to a recursively defined sequence to prove convergence and identify the limit.

  • Define limsup and liminf via ε-characterizations and prove that lim a_n exists iff limsup a_n = liminf a_n.

Your checkpoint

A one-page 'toolkit' sheet listing the completeness, nested interval, Bolzano–Weierstrass, and monotone convergence statements plus a worked ε-N proof template, verified by re-deriving two of the theorems from memory in under 20 minutes.

Week 3

Sequences, Series, and Limits

  • Prove the Cauchy criterion for sequences and give an example of a Cauchy sequence in a non-complete setting to show why completeness matters.

  • Apply the comparison, ratio, root, and integral tests to at least eight series, justifying convergence or divergence in each case with the hypotheses checked.

  • Prove absolute convergence implies convergence, and construct a conditionally convergent series whose terms can be rearranged to a different sum.

  • Prove the alternating series test and estimate the remainder for a specific series with an explicit error bound.

  • Compute limits of sequences using standard limits, Stolz–Cesàro or l'Hôpital-style reductions where legitimate, and justify each substitution.

Your checkpoint

A graded-style problem set of 12 series problems solved end to end, each with hypothesis verification, conclusion, and a one-line statement of which test was used and why it applies.

Week 4

Continuity and Uniform Continuity & Proof Technique and Rigorous Argumentation

  • Write the ε-δ definition of continuity and prove continuity of polynomials, rational functions off their zeros, and compositions from the definitions.

  • Distinguish pointwise from uniform continuity with a proof that f(x) = x² is not uniformly continuous on R but is on [0, 1], using the sequential criterion.

  • Prove that continuous functions on compact intervals attain their extrema and are uniformly continuous there (Heine–Cantor), citing compactness correctly.

  • Apply the intermediate value theorem to prove existence of roots, and use the extreme value theorem to justify optimization claims.

  • Identify and repair three common logical errors in continuity proofs (choosing δ after ε-dependent quantities, confusing pointwise with uniform, ignoring domain restrictions).

Your checkpoint

A two-column comparison table of pointwise vs. uniform continuity (definition, sequential criterion, examples, counterexamples, preservation under operations) plus four fully written proofs, including the Heine–Cantor theorem.

Week 5

Differentiation and Mean Value Theorems

  • Prove differentiability implies continuity, and give an example of a continuous nowhere-differentiable-in-a-point function to separate the notions.

  • Derive the product, quotient, and chain rules from the limit definition, stating each hypothesis.

  • State and prove Rolle's theorem, then derive the mean value theorem and use it to prove that a function with zero derivative on an interval is constant.

  • Apply the MVT and Cauchy MVT to prove inequalities and to establish l'Hôpital's rule for the 0/0 case.

  • Prove Taylor's theorem with Lagrange remainder and use it to bound approximation error for a specific function.

Your checkpoint

A single written proof chain: Rolle → MVT → Cauchy MVT → Taylor with remainder, each implication fully justified, plus two applied problems (an inequality proved by MVT and an error bound from Taylor).

Week 6

Riemann and Improper Integration & Sequences and Series of Functions; Uniform Convergence

  • Prove integrability of continuous functions on closed intervals using uniform continuity and Riemann sums, and state the Darboux criterion for integrability.

  • Prove the fundamental theorem of calculus in both parts, carefully tracking which hypotheses (continuity, integrability) are needed for each.

  • Evaluate improper integrals of both types, deciding convergence with comparison and limit tests, and prove convergence or divergence for at least five examples.

  • Distinguish pointwise from uniform convergence of function series, and prove the Weierstrass M-test and use it on a power series.

  • Prove that uniform convergence preserves continuity and permits term-by-term integration, and give a counterexample showing pointwise convergence does not.

Your checkpoint

A concept map linking Riemann integrability, FTC, improper integrals, pointwise vs. uniform convergence, and the M-test, where every arrow is labeled with the theorem that justifies it, accompanied by three fully written proofs.

Week 7

Metric Spaces, Topology of R^n, and Compactness

  • Verify the metric space axioms for R^n with Euclidean, taxicab, and sup metrics, and prove that the three are equivalent for convergence.

  • Prove that compactness, sequential compactness, and closed-and-bounded are equivalent in R^n (Heine–Borel), and identify which implications fail in general metric spaces.

  • Determine openness, closedness, closure, interior, and boundary for at least six concrete subsets of R², justifying each claim with a proof or counterexample.

  • Prove that continuous images of compact sets are compact and that continuous real-valued functions on compact sets attain extrema.

  • Use the Baire category or nested compact set argument to prove a nonempty intersection result, and explain where completeness is used.

Your checkpoint

A topology worksheet: a table of eight subsets of R² with open/closed/compact/connected verdicts and a proof sketch per cell, plus three complete theorem proofs (Heine–Borel, continuous image of compact, extreme value theorem).

Week 8

Multivariable Calculus: Derivatives, Inverse and Implicit Function Theorems & Proof Technique and Rigorous Argumentation

  • Compute partial derivatives, gradients, Jacobians, and directional derivatives for multivariable functions, and verify differentiability via the linear approximation definition rather than partials alone.

  • Prove the chain rule in several variables and use it to compute derivatives of compositions.

  • State and apply the inverse function theorem, checking the nonvanishing Jacobian hypothesis, and compute the derivative of an inverse map.

  • State and apply the implicit function theorem to solve for one variable in terms of others, verifying hypotheses, and compute implicit derivatives.

  • Assemble a timed 3-hour mock exam covering all nine domains and grade it against a rubric, logging every lost point by domain.

Your checkpoint

A completed timed mock exam with a self-graded score report broken down by domain, plus a one-page error log listing each mistake, its root cause, and the specific theorem or definition to review before exam day.

Milestones

Week 2: Can state and prove the completeness axiom's key consequences (Archimedean property, density of Q, Bolzano–Weierstrass) and write a correct ε-N proof for a new sequence in under 15 minutes without notes.

Week 4: Can write the ε-δ definition, prove Heine–Cantor from compactness, and correctly distinguish pointwise from uniform continuity on three unseen examples, scoring at least 8/10 on a self-made continuity quiz.

Week 6: Can prove both parts of the FTC and the Weierstrass M-test from memory, and correctly classify five unseen function series as uniformly convergent or not with justification.

Week 8: Scores at least 70% on the timed 3-hour mock exam with no domain below 50%, and the error log shows each weak domain mapped to a specific theorem or definition to re-review.