first of all i am doing programs in java language  this code is merely taken from web site
 i have not question about divide and conqurer  algorithms but about  function and it's argument here is code of ternary search
def ternarySearch(f, left, right, absolutePrecision):
    #left and right are the current bounds; the maximum is between them
    if (right - left) < absolutePrecision:
        return (left + right)/2
    leftThird = (2*left + right)/3
    rightThird = (left + 2*right)/3
    if f(leftThird) < f(rightThird):
        return ternarySearch(f, leftThird, right, absolutePrecision)
    return ternarySearch(f, left, rightThird, absolutePrecision)
i am not asking once again how implement it in java  i am asking for example how define function?for example let  y=x^+3 yes  we can determine it as
public static int y(int x){
 return x*x+3;
}
but 
here 
 return ternarySearch(f, leftThird, right, absolutePrecision)
function f does not have argument and how do such?please help me