Lectures for Mathematics 112, Fall 2025-26

  • M 9/1: Labor Day Holiday
  • T 9/2: Overview
  • W 9/3: Skim through Ch1
  • F 9/5: Start 2.1: Binary operators, identity, inverses, associativity

  • M 9/8: Polygon triangulations and product parenthesizations in connection with 2.30 and 2.31, noncommutative computer "and", nonassociative computer "*", (Z_n,+,*) questions about homework
  • T 9/9: Continue through 2.3 field axioms, 2.4 some of their consequences
  • W 9/10: Finish 2.4, go over homework
  • F 9/12: [Add/section-change deadline] 2.5 Subtraction and division

  • M 9/15: Finish 2.5, start order
  • T 9/16: Go over homework, start 2.6 through inequalities
  • W 9/17: Finish inequalities, start absolute value
  • F 9/19: Finish absolute value; inductive sets, the natural numbers of a field

  • M 9/22: Induction theorem, addition and multiplication in the integers of a field, no natural number between 0 and 1
  • T 9/23: Least Integer Principle; no square root of 2 in the rational field
  • W 9/24: Recursive definitions, a^{m+n} = a^m a^n for all natural n,m, go over homework
  • F 9/26: The integers and rational numbers of a field; finish 3.3

  • M 9/29: Discuss first exam; numerically unstable sequence; 4.1 the complexification of a field with no square root of -1
  • T 9/30: Skim 4.2 complex conjugate, start 5.1 sequences and binary search sequences
  • W 10/1: Go over homework, start binary search
  • F 10/3: More binary search, pth roots

  • M 10/6: [No-W drop deadline] Review the binary searches and their consequences, rational exponents, begin into chapter 6
  • T 10/7: More chapter 6: triangle inequality, geometry of complex addition, geometry of complex multiplication, roots of unity
  • W 10/8: Addition laws for cosine and sine, polar decomposition of nonzero complex numbers, finding the nth roots of a nonzero complex number
  • F 10/10: Complex mappings, work on exercises 6.35, 6.40a as revised on the assignments page for this course

  • M 10/13: Full triangle inequality writeup, first few pages of chapter 7 and then start complex sequences writeup: complex sequences form a ring, bounded complex sequences a subring
  • T 10/14: The null sequences form an ideal of the bounded sequences, convergence in terms of nullness, convergent sequences are bounded, sum rule and product rule
  • W 10/15: Review sum rule and product rule, (r^n), (b^{1/n}), (a_n^\alpha), preview Friday's homework problems from chapter 7
  • F 10/17: Finish r^n rule, b^{1/n} rule, 1/n^\alpha rule, x_n^\alpha rule, reciprocal rule

  • Fall break week

  • M 10/27: Interesting case of the geometric sequence theorem via the fact that a convergent sequence is Cauchy; geometric series; relation between area and circumference of the unit disk
  • T 10/28: Limit of nonnegative sequence is nonnegative, index-translate of a sequence has the same convergence, Fibonacci quotient example
  • W 10/29: Monotonic sequence theorem, point to various formulations of completeness
  • F 10/31: Binomial theorem and {n^(1/n)}, review chapter 7

  • M 11/3: Continuity: examples from early chapter 8, continuity of the rational power function
  • T 11/4: Progenitive continuity results, start the limit of a function
  • W 11/5: Every f:Z->C continuous? f(p/q)=1 but f(x)=0 for irrational x?
  • F 11/7: Function limit as common sequence limit, derivative of the squaring function as a function limit, three subtle function limits

  • M 11/10: [Withdraw/leave deadline] Review continuity and function limits
  • T 11/11: Intermediate Value Theorem; Extreme Value Theorem
  • W 11/12: Work on chapter 9 exercises
  • F 11/14: Start derivatives, derivative of the rational power function

  • M 11/17: Generative derivative rules, including chain rule
  • T 11/18: Mean value theorem and its consequences, x/2+x^2 sin(1/x) example
  • W 11/19: Start series: harmonic series diverges, nth term test, comparison test
  • F 11/21: p-test, {|z|t^n/n!} summable, absolute convergence test

  • M 11/24: Limit-comparison test, ratio test, alternating series test, start power series
  • T 11/25: Power series radius of convergence
  • W 11/26: Differentiation theorem
  • F 11/28: Thanksgiving Holiday

  • M 12/1: Start specific power series examples
  • T 12/2: More power series examples
  • W 12/3: More power series examples
  • F 12/5: Values of zeta

  • M 12/8: Values of zeta
  • T 12/9: No meeting (college on Thursday schedule)
  • W 12/10: Loose ends

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