Open Middle®
Directions: Fill in the boxes below using the digits 1 to 9, at most one time each, to make as many possible solutions as you can.
Hint
What values of trig functions give “easy to work with” solutions?
Answer
One possible answer: 4sin(x) and f'(6pi/3)
Source: Chris Luzniak
This raised an interesting question – what effect would allowing the integers from -9 to 9 have on the number of solutions? It would allow use to repeat integers providing one was negative as well as the positive and negative solution sets