That is to say, this cubic function is monotonous on R.

Lenovo g(x)=x?

Easy to get, the cubic function that satisfies the meaning of the question can only be f(x)=a(x-h)? +k In this form,

Then try to get the parameters according to other conditions.

Ps: You gave too few conditions and only got so much information.

Have fun! I hope I can help you. If you don't understand, please ask. I wish you progress in your study! O(∩_∩)O