Sorry, I was just looking on at this question and was wondering what happens in b) at the horizontal point of inflexion?
Because the gradient is 0 there would we bring f'(x) to approach 0 as though y = 0 were an asymptote (after the 3rd root)?
Or is this completely wrong?
Anyway, I hope my question makes some sort of sense
Almost right, but it would actually touch the y-axis! It actually turns back around on itself - You'll draw a turning point that
just touches the x-axis, if that makes sense?
this is because the gradient goes from positive, to 0, back to positive (or replace positive with negative, depending on the function). This corresponds to the curve coming towards the axis, just touching it, then turning back around