QUESTION 1 Let f(x) = x1/3(x - 4) . Find all values of x for which (x) = 0 or (x) is undefined. As your answer please input the sum of all values of X satisfying f( X) - or f( x) is undefined. QUESTION 2 x2 Let f (x ) = Find all critical points of f. As your answer please input the sum of all critical points. 4 ( x+ 1 ) QUESTION 3 Let f (x) = - x3+ 2x2+ 2. Find an open interval (a, b) on which f increases. As your answer please input a + b in decimal form with three significant digits after the decimal point