Submitted by mrmonkey on Wed, 01/10/2018 - 19:41
Forums:
How do you know that the curve has rotational symmetry of 2 around the inflection point, apart from it being implied for the last result to be correct? Would you have to show that it does in the exam, or could you just state it?
Stating ok
In this case, you could just state the symmetry (just make sure your sketch looks like it does actually have this rotational symmetry).
All cubics have rotational symmetry (see: https://nrich.maths.org/431/solution), but you would not be expected to prove this in the exam.
thanks
Hadn't known all cubics have rotational symmetry thanks for the website link explaining it