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Permanent link to this puzzle: mscroggs.co.uk/puzzles/100

Source: Futility Closet

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

If you enjoyed this puzzle, check out Sunday Afternoon Maths LXII,

puzzles about floors, or a random puzzle.

puzzles about floors, or a random puzzle.