Problem 1111111 · The Circle That ReturnsPrint one blank worksheet now, download its PDF, or prepare a family or classroom packet.
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The Circle That Returns

Complete to collectJade CabochonLevel 3 · 6 Glints

Meditations on Oneness · Local folio mark 1111111

At the Observatory, Luna records a brass window whose six markers are spaced by equal turns. For an angle , write

This is the point at angle on the unit circle. Angles differing by name the same point.

Luna Tessell stands at an Observatory worktable with her field notebook. Beside her is a large brass circular instrument with six blank ivory markers spaced evenly around its rim.
Luna records the window before naming its algebra.

Field plate · Rules for this investigation

Let . Then and .

A regular hexagon inscribed in a circular Observatory window. Its six vertices are marked at 0, 60, 120, 180, 240, and 300 degrees, with blank parchment labels beside them for student notation.
Write both the name and the matching power of at every vertex.

Label the window here. Use separate paper for the proof.

  1. Label the six vertices with and . Prove that these six points are all the solutions of .

    For the “no others” part, write . What must force and to be?

Local folio mark 1111111 · Meditation 7 The Circle That Returns

Luna's trace record · Repeated multiplication

Because , exponents differing by 6 name the same root. For example, .

Starting at , repeatedly multiply by the root in the first column. Record the exponents visited before returning to 0.

Some traces close early. The complete state record will show which ones.

Complete the cycle record on this page.

  1. A root is a generator when its repeated powers visit all six roots.

    Complete the table. Which roots are generators?

    Multiplier Exponents visited, beginning with 0 First return after Visits all six?
Local folio mark 1111111 · Meditation 7 The Circle That Returns

Archive synthesis · One object, one operation

A group is a set with an operation having these properties:

  • multiplying two members stays in the set;
  • parentheses do not change the result;
  • one identity leaves every member unchanged;
  • every member has an inverse that multiplies with it to give the identity.

You may use the fact that complex multiplication is associative.

Use separate paper for your group proof.

  1. Prove that the six solutions of form a group under multiplication.

    Use and reduce exponents modulo 6. Name the identity and the inverse of every . Finally, explain why this group is cyclic: one root’s repeated powers produce every root.

At a glance

About this problem

These tags show what the problem is about and the math you’ll use. Choose one to find similar problems.

Theme

Skills

Grade

Math area

Topics

Is this a good fit?

Before you choose this problem

A plain-language look at readiness, thinking, time, and the expected response.

Math readiness

Designed for Grade 11 · Grade 12

Uses HS DISC math.

Thinking

Stretch challenge

A nontrivial plan using familiar mathematical ideas.

Time & response

About 18–40 minutes

Heavy amount of written work · Proof response.

How to support: The central move is to treat multiplication as addition of turn angles. Encourage exponent sequences modulo 6 without naming the two generator rows.

Keep exploring

The Manyfold challenge 20 of 22

Technical reference

Rating, skills & curriculum

Designed for Grade 11 · Grade 12 · Uses HS DISC math · About 18–40 minutes

Grade 11 · Grade 12 · Number and quantity · Algebraic structure and equations · Complex numbers and vectors · Algebraic structures

MJ HS:DISC.6 · C3 · W3

Precise MJD coordinates, factor scores, skill weights, calibration evidence, and curriculum crosswalks. This reference is available to everyone and is intentionally last.

Content level

MJ HS:DISC.6

High school

HS DISC · point 6

Likely range
MJ HS:DISC.5–HS:DISC.7
Confidence
68%

Challenge

C3 · Stretch

A nontrivial plan using familiar mathematical ideas.

  • Method selection2
  • Reasoning depth3
  • Novelty3
  • Constraint management2
  • Proof or justification3

Workload

W3 · Heavy

Sustained mathematical work and a substantial written response.

Active time
18–40 minutes · typically 27
Response
Proof
Known-method steps
24
  • Mechanical execution2
  • Written output3
  • Representation production2
  • Bookkeeping2

Learning focus

Skills this problem practices

What a successful response demonstrates, with each skill’s share of the content rating.

  • Represent complex numbers in polar form and connect multiplication to rotation

    The learner can represent complex numbers in polar form and connect multiplication to rotation. This capability is distinct from mere exposure to or isolated use of complex arithmetic; trig.

    • Developing mastery
    • 52% focus
    • MJ HS:PRE.4 milestone
  • Reason with group axioms and symmetry operations

    Recognize and use closure, associativity, identity, and inverses in a small group, including a symmetry group or operation table.

    • Developing mastery
    • 48% focus
    • MJ HS:DISC.6 milestone

External alignment

Curriculum and standards crosswalks

Approved evidence-backed locations that support discovery. They do not define the MathJewels rating.

Common Core State Standards for Mathematics2010 · 1 location
Clusters1 location · Representative: Represent complex numbers and their operations on the complex plane.