Consider the function f left parenthesis x right parenthesis equals short dash 1 fourth x to the power of 4 minus x cubed. On what interval(s) is f open parentheses x close parentheses both decreasing and concave up? open parentheses 0 comma space infinity close parentheses open parentheses short dash 2 comma space infinity close parentheses open parentheses short dash 2 comma space 0 close parentheses open parentheses short dash 3 comma space infinity close parentheses