Quadratics
(Eingestellt am 23. Februar 2026, 03:41 Uhr von Prof.Dori)
Quadratics
Rules:
Normal sudoku rules apply.
Quads: Each circle contains four invisible digits (not necessarily distinct and to be deduced). These must each appear in the surrounding four cells.
Quadratics: Of the four digits on a circle, two of them are the two solutions of X^2 - aX + b = 0, where a and b are the other two digits on that circle. If the equation has only one solution, that digit occurs twice.
Click here to start the puzzle
Lösungscode: Row 9.
Kommentare
am 24. Februar 2026, 14:29 Uhr von bboom
Absolutely impressive that you created this, but honestly it wasn't a great puzzle to solve. For me it basically came down to brute forcing a list of valid quads, and then just crossing off the options for each location, which felt mostly time-consuming rather than hard.
am 24. Februar 2026, 13:54 Uhr von Franjo
I needed some preparation on paper, but then got into a nice flow… Thank you very much for creating and sharing this great math-puzzle.
am 24. Februar 2026, 07:36 Uhr von VolpeRosso
Haha - a very fun puzzle for those quadratically inclined. But... just when one has solved all the equations, and done most of the sudoku... and you're barelling towards the end... There's that sting in the tail! <3
am 24. Februar 2026, 03:33 Uhr von mbumbee
Lovely!! This puzzle isn't for everyone, but that should be clear from the very beginning - and if it's not for you it's ok to move on!
am 23. Februar 2026, 23:40 Uhr von Myxo
Lovely! And with the right math tricks, no notes are needed :)
am 23. Februar 2026, 23:37 Uhr von QuiltyAsCharged
Finish your maths homework first, then you can play your puzzle game!
am 23. Februar 2026, 23:36 Uhr von Fool on Hill
Excellent puzzle. But no way is this 4/5. I did need to do some initial thinking, but after that it solved like a dream with no issues until a slightly technical (perhaps 3/5) ending. I was amazed that it did solve - I am sure there are some uniqueness points buried in there (at least 8 different digits have to be on circles, otherwise there are two you can't distinguish), but that thinking did not cross my mind till I'd solved it.
am 23. Februar 2026, 15:53 Uhr von Yann
Funny, thanks !
am 23. Februar 2026, 13:55 Uhr von Mennoo_
Very interesting concept for a puzzle.
I think the puzzle really requires a page for notes. But with that a loveky solve. Nice setting as well! Loved that
