What's the format of the answer?
It's a very simple question, but it just won't accept answer which
I know to be correct in any format I tried.
It should be an integer.
ynori7 wrote: It should be an integer.
f(x) = ax^2 + 12x + 1
Given that the maximum value of the curve generated by the above equation is f(x)=7, what is the value of a?
There are no integer values of a for which this function maxes out at x=7, even if we restrict it to integer xs.
For real numbers, that a is a fraction (and f(7) is then integer, but that doesn't get accepted either).
taw wrote: There are no integer values of a for which this function maxes out at x=7, even if we restrict it to integer xs.
False. There is an integer value which produced a max (y=7) at some x value (let's call that value of x "b" ). Not only is b an integer too, but the values of y at b+1 and b-1 are also integers.
Try using some basic calculus to produce a second equation. Then you'll have two equations and two unknowns (a and x).