STEP 2013: 23 of 26 questions decoded, by method & chapter.

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The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.

• 1Sweeping Lines for Root CountsKey methodPureFunctions & Curve Sketching4 other sittings

  Same method, other sittings

  2006201120142021

  Worked solutionOpen the method
• 2Reduction Formulae & TelescopingKey methodPureIntegration6 other sittings

  Same method, other sittings

  200920152016201720202023

  Worked solutionOpen the method
• 3Sweeping Lines for Root CountsKey methodPureFunctions & Curve Sketching4 other sittings

  Same method, other sittings

  2006201120142021

  Worked solutionOpen the method
• 5Symmetry → Turning PointsKey methodPureFunctions & Curve Sketching3 other sittings

  Same method, other sittings

  200920122015

  Worked solutionOpen the method
• 6Interleaved Monotone SubsequencesKey methodPureSequences & Series2 other sittings

  Same method, other sittings

  20232024

  Worked solutionOpen the method
• 7Reuse the Earlier ResultExhaust the Factor PairsPavlovPureProof & Number Theory8 other sittings

  Same method, other sittings

  20082009201120162019202020232024

  Worked solutionOpen the method

  AlsoExhaust the Factor Pairs
• 8The Sketch Is the ProofKey methodPureFunctions & Curve Sketching2 other sittings

  Same method, other sittings

  20112018

  Worked solutionOpen the method
• 9Limiting EquilibriumTunnelMechanics10 other sittings

  Same method, other sittings

  2006201220142017201820192020202220232024

  Worked solutionOpen the method
• 10Projectiles → Split by AxisTunnelMechanics11 other sittings

  Same method, other sittings

  20062008200920102012201420172020202220232024

  Worked solutionOpen the method
• 111D Collisions → Two ScalarsTunnelMechanics8 other sittings

  Same method, other sittings

  20062008200920112018201920222025

  Worked solutionOpen the method
• 12Variance via CovariancesKey methodProb & StatsProbability & Statistics3 other sittings

  Same method, other sittings

  200620162017

  Worked solutionOpen the method

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The paper at a glance, coloured by move. Click a square to open its question; empty squares are not decoded yet.

• 1Integral → Linear SystemKey methodPureIntegration1 other sitting

  Same method, other sittings

  2017

  Worked solutionOpen the method
• 2Leibniz → Maclaurin RecurrenceKey methodPureDifferential Equations1 other sitting

  Same method, other sittings

  2009

  Worked solutionOpen the method
• 3The Vanishing Vertex-SumKey methodPureVectors & Matrices4 other sittings

  Same method, other sittings

  2012201920212023

  Worked solutionOpen the method
• 4Roots of Unity FactorisationKey methodPureComplex Numbers1 other sitting

  Same method, other sittings

  2016

  Worked solutionOpen the method
• 5Infinite Descent & IrrationalityKey methodPureProof & Number Theory4 other sittings

  Same method, other sittings

  2011201520222023

  Worked solutionOpen the method
• 6Modulus Bounds → ImpossibilityKey methodPureComplex Numbers1 other sitting

  Same method, other sittings

  2022

  Worked solutionOpen the method
• 7First Integral via EnergyKey methodPureDifferential Equations1 other sitting

  Same method, other sittings

  2012

  Worked solutionOpen the method
• 8Focus-Directrix Polar FormKey methodPureCoordinate Geometry & Conicsonly this sitting

  Same method, other sittings

  This one has only struck here so far.

  Worked solutionOpen the method
• 9Spotting SHMKey methodMechanics4 other sittings

  Same method, other sittings

  2009201520162020

  Worked solutionOpen the method
• 10Moment of Inertia → RotationTunnelMechanics5 other sittings

  Same method, other sittings

  20062008201220152018

  Worked solutionOpen the method
• 11Stability via Potential EnergyKey methodMechanics4 other sittings

  Same method, other sittings

  2006201820202022

  Worked solutionOpen the method
• 12Indicators + Linearity of ExpectationKey methodProb & StatsProbability & Statistics4 other sittings

  Same method, other sittings

  2008201120212024

  Worked solutionOpen the method