The general form of a quadratic equation is a*x^2 + b*x + c = 0. Define a function that when passed the coefficients a, b and c and a fourth boolean attribute flag, returns, 1. None, if no solution exists; 2. the higher of the two roots of the equation, if flag is True and solution exists; 3. the smaller of the two roots of the equation, if flag is False and solution exists. You can use the built-in max(), min() and math.sqrt() functions. NOTE: The challenge of this question is in the research and not the implementation.