sir/maam it's given that cubic polynmail isnt in course should w do it

You have studied factorisation of cubic poly since class 8/9 with some formulae. You also have studied the factor thm.

 So factorising a cubic poly is just the conbination of these two methods.

 So it's better from further studies point of view that you learn it as it's very simple and you know about it already.

 So if you are stuck on any question, do send it to us. We'll help you in that.