Quick query! (1 Viewer)

[SharkeyBoy]

Hey,
For questions that ask "Find all stationary points of f(x)"
Do we have to find possible inflexion points as well?
because for some questions, it says this and then the next question will say something like "Find the inflexion point of f(x)"
So do we find both just to be safe, because I'm pretty sure an inflexion point is a stationary point, yet they've asked 2 questions...

 

[andybandy]

station points is when f'(x) = 0
inflection points is when f''(x) = 0

 

[Mata10]

Well the difference is that in order to find stationary point you have to differentiate once so f'(x), whereas, for inflexion point you have to do it twice f''(x).

 

[SharkeyBoy]

yeah yeah, i know the difference
So if the question only says find "all stationary points", we only do f'(x), not f''(x) ?

 

[andybandy]

if no other question below it asks for inflection points, then you can do it optionally to help with the sketch of the graph

 

[SharkeyBoy]

if no other question below it asks for inflection points, then you can do it optionally to help with the sketch of the graph

hmm ok, makes sense, that's probably what i was going to do anyway. cheers

 

[andybandy]

hmm ok, makes sense, that's probably what i was going to do anyway. cheers

all goods