Open Middle®
Directions: Using the digits 1 to 9, at most one time each, place a digit in each box to create a function such that at x = 2, the derivative (at that point) would fall in the interval of {0, 48}
Hint
One might consider solving the equation at the extremes and means of the interval of solutions
Sometimes small numbers are easier to start with
Answer
Reading left to right in image one (near largest I believe) solution is: {4, 3}
Source: Gregory L. Taylor, Ed.D.