f(x) = min(2x2,52-5x)
The maximum possible value of this function will be attained when 2x2 = 52-5x.
2x2+5x-52 = 0
(2x+13)(x-4)=0
⇒ x = -13/2 or x = 4
Since x has to be positive integer, we can discard the case x = -13/2
x = 4 is the point at which the function attains the maximum value.
putting x = 4 in the original function, we get, 2x2 = 2*42 = 32.
Or the maximum value of f(x) = 32