单项选择题
A cubic function is a polynomial of degree 3; that is, it has the form
， where a≠0. Then ( ) is false.
A、A cubic function can have no critical number.
B、A cubic function can have 2 critical numbers.
C、x=1 is critical number when the cubic function has only one critical number.
D、x=0 is critical number when the cubic function has only one critical number.
A cubic function is a polynomial of degree 3; that is, it has the form
， where a≠0. Then ( ) is false.A、A cubic function can have no critical number.
B、A cubic function can have 2 critical numbers.
C、x=1 is critical number when the cubic function has only one critical number.
D、x=0 is critical number when the cubic function has only one critical number.
的一个基础解系：
