mscroggs.co.uk
mscroggs.co.uk

subscribe

Puzzles

Arctan

Prove that \(\arctan(1)+\arctan(2)+\arctan(3)=\pi\).

Show answer & extension

If you enjoyed this puzzle, check out Sunday Afternoon Maths XXXVIII,
puzzles about geometry, or a random puzzle.

Archive

Show me a random puzzle
 Most recent collections 

Advent calendar 2025

Advent calendar 2024

Advent calendar 2023

Advent calendar 2022


List of all puzzles

Tags

integration dates digital clocks cube numbers square roots symmetry crosswords ave advent time irreducible numbers integers spheres people maths graphs fractions chocolate consecutive numbers cryptic clues coins dice geometric means median complex numbers partitions differentiation consecutive integers surds odd numbers trigonometry powers ellipses quadratics calculus digits taxicab geometry regular shapes geometric mean cryptic crossnumbers unit fractions grids doubling probability coordinates money colouring expansions elections hexagons triangles digital products axes floors lists sets division games books circles factors proportion clocks area numbers rectangles speed pentagons dodecagons mean averages lines balancing pascal's triangle palindromes rugby christmas xor cubics shapes bases squares combinatorics logic 2d shapes shape sequences dominos angles algebra tournaments prime factors multiplication routes menace cards binary polynomials volume wordplay percentages chess chalkdust crossnumber albgebra tangents range sums means 3d shapes probabilty star numbers polygons products decahedra parabolas determinants multiplaction squares triangle numbers crossnumbers planes sum to infinity multiples neighbours square grids matrices square numbers remainders prime numbers the only crossnumber perimeter functions number addition arrows gerrymandering factorials geometry perfect numbers quadrilaterals sport tiling medians even numbers scales folding tube maps indices

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2026