当x<=0时,f(x)=f(-x)=-x^(1/3)(x<等于0)所以,当X>=0时 f(X)=F(X)=X^(1/3) 当x<=0时 f(x)=f(-x)=-x^(1/3)单调性可通过求导解决 f'(x)=(1/3)x (当X>=0时)可看出f'(x)>=0恒成立,因此,函数f(x)在[0,正无穷)递增,同理可推出,f(x)在(负无穷,0]递减.
f(x)=f(-x)=-x^(1/3){x<0}在(-。。,0]递减,由对称知在(0,+。。)递增