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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematical Methods CAS => Topic started by: VCE_2012 on October 29, 2012, 08:33:27 pm

Title: Using double derivatives to show/find the nature of a stationary point?
Post by: VCE_2012 on October 29, 2012, 08:33:27 pm
Are specialist students (or students who know about it) are permitted to use double derivatives to show/find the nature of a stationary point?
To what extent are students allowed to apply their specialist skills into methods? 
Title: Re: Using double derivatives to show/find the nature of a stationary point?
Post by: Bhootnike on October 29, 2012, 09:32:04 pm
Are specialist students (or students who know about it) are permitted to use double derivatives to show/find the nature of a stationary point?
To what extent are students allowed to apply their specialist skills into methods?
yea, and you can use uni maths if you want to according to someone who got 50 and 42 in methods/spesh respectively that I asked the same question to.
Title: Re: Using double derivatives to show/find the nature of a stationary point?
Post by: FlorianK on October 29, 2012, 09:52:30 pm
Are specialist students (or students who know about it) are permitted to use double derivatives to show/find the nature of a stationary point?
To what extent are students allowed to apply their specialist skills into methods?
Yes, you are allowed to. However I don't really think it's faster and secondly it doesn't always work e.g. x^4. Using second derivative test won't give you an advantage
Title: Re: Using double derivatives to show/find the nature of a stationary point?
Post by: Bhootnike on October 29, 2012, 10:16:10 pm
Are specialist students (or students who know about it) are permitted to use double derivatives to show/find the nature of a stationary point?
To what extent are students allowed to apply their specialist skills into methods?
Yes, you are allowed to. However I don't really think it's faster and secondly it doesn't always work e.g. x^4. Using second derivative test won't give you an advantage

well, if its a nice question, its much faster!
however as seen in the vcaa 2009 exam 2, question 2, they might be nasty and make it so d^2y/dx^2 = 0 :p
so best to know both techniques i guess
Title: Re: Using double derivatives to show/find the nature of a stationary point?
Post by: BigAl on October 30, 2012, 08:43:26 pm
I hate it when a question restricts you to use a specific way. Everyone thinks differently and so everyone can derive their own methods. What's the purpose of this restriction? I don't understand. Maths is logical way of interpreting things..but vcaa sometimes makes it something pointless.
Title: Re: Using double derivatives to show/find the nature of a stationary point?
Post by: Bhootnike on October 30, 2012, 08:46:52 pm
 ^ amen
Title: Re: Using double derivatives to show/find the nature of a stationary point?
Post by: Jenny_2108 on October 30, 2012, 08:58:28 pm
Are specialist students (or students who know about it) are permitted to use double derivatives to show/find the nature of a stationary point?
To what extent are students allowed to apply their specialist skills into methods?
Yes, you are allowed to. However I don't really think it's faster and secondly it doesn't always work e.g. x^4. Using second derivative test won't give you an advantage

well, if its a nice question, its much faster!
however as seen in the vcaa 2009 exam 2, question 2, they might be nasty and make it so d^2y/dx^2 = 0 :p
so best to know both techniques i guess

I don't understand what both of you are talking about = = Just have a look vcaa 09 Ex2, q2 and dunno where are x^4 and dy^2/d^2x
Title: Re: Using double derivatives to show/find the nature of a stationary point?
Post by: Bhootnike on October 30, 2012, 09:22:08 pm
Are specialist students (or students who know about it) are permitted to use double derivatives to show/find the nature of a stationary point?
To what extent are students allowed to apply their specialist skills into methods?
Yes, you are allowed to. However I don't really think it's faster and secondly it doesn't always work e.g. x^4. Using second derivative test won't give you an advantage

well, if its a nice question, its much faster!
however as seen in the vcaa 2009 exam 2, question 2, they might be nasty and make it so d^2y/dx^2 = 0 :p
so best to know both techniques i guess

I don't understand what both of you are talking about = = Just have a look vcaa 09 Ex2, q2 and dunno where are x^4 and dy^2/d^2x

Um.
florian and I werent speaking of the same question ;)
The question I am talking about was such that if you found the second derivative, and subbed in the given value, it = 0. making the second derivative inconclusive. :)