Login

Welcome, Guest. Please login or register.

October 14, 2025, 08:45:14 am

Author Topic: Families of functions question  (Read 5212 times)  Share 

0 Members and 1 Guest are viewing this topic.

xce

  • Victorian
  • Adventurer
  • *
  • Posts: 5
  • Respect: 0
Families of functions question
« on: February 26, 2008, 10:07:53 pm »
0
Hi all,

We have been given an assignment on Chapter 3: Families of functions (Essential Math Methods 3&4 textbook). I have been able to answer all questions on the assignment easily (the assignment is quite easy), apart from one of them. Any help is appreciated.

Express in the form

Thanks!

bucket

  • Victorian
  • Part of the furniture
  • *****
  • Posts: 1005
  • Respect: +8
Re: Families of functions question
« Reply #1 on: February 26, 2008, 10:10:41 pm »
0
i know this one!..i think?

editsorry, it turns out i only know how to work it out without the coefficients too =\ lol. how embarrasing







thats as far as I can go =\ sorry.
« Last Edit: February 26, 2008, 10:37:14 pm by bucket »
Monash University
Science/Engineering (Maths, Physics and Electrical Engineering)

xce

  • Victorian
  • Adventurer
  • *
  • Posts: 5
  • Respect: 0
Re: Families of functions question
« Reply #2 on: February 26, 2008, 10:13:12 pm »
0
Heard of the question? It's from the assignment they ship on the Teacher's CD-ROM. I'd imagine quite a few schools use it.

I should also add that the textbook gives an example on how to do it, but only for questions where there is no coefficient in front of the x term. Therefore, the example was unhelpful.

AppleXY

  • Life cannot be Delta Hedged.
  • Victorian
  • ATAR Notes Superstar
  • ******
  • Posts: 2619
  • Even when the bears bite, confidence never dies.
  • Respect: +16
Re: Families of functions question
« Reply #3 on: February 26, 2008, 10:22:04 pm »
0
--> Disregard. Miscalc.
« Last Edit: February 26, 2008, 10:54:01 pm by AppleXY »

2009 - BBus (Econometrics/Economics&Fin) @ Monash


For Email: click here

Need a question answered? Merspi it!

[quote="Benjamin F

bucket

  • Victorian
  • Part of the furniture
  • *****
  • Posts: 1005
  • Respect: +8
Re: Families of functions question
« Reply #4 on: February 26, 2008, 10:40:08 pm »
0
apple are you sure that is right? because when I put your equation into the calculator with x=2, it doesn't get the same answer as the original equation.
Monash University
Science/Engineering (Maths, Physics and Electrical Engineering)

AppleXY

  • Life cannot be Delta Hedged.
  • Victorian
  • ATAR Notes Superstar
  • ******
  • Posts: 2619
  • Even when the bears bite, confidence never dies.
  • Respect: +16
Re: Families of functions question
« Reply #5 on: February 26, 2008, 10:49:50 pm »
0
Disregard. Something went terribly wrong. Sorry, I have to check over it again, but now I gotta do my Identity & Belonging crap for english. :P

2009 - BBus (Econometrics/Economics&Fin) @ Monash


For Email: click here

Need a question answered? Merspi it!

[quote="Benjamin F

dcc

  • Victorian
  • Part of the furniture
  • *****
  • Posts: 1198
  • Respect: +55
  • School Grad Year: 2008
Re: Families of functions question
« Reply #6 on: February 26, 2008, 10:53:00 pm »
0
I'd do it using long division, as such:

           



       

Remainder:

Thus remembering our form for dividing:







« Last Edit: February 26, 2008, 11:07:12 pm by dcc »

AppleXY

  • Life cannot be Delta Hedged.
  • Victorian
  • ATAR Notes Superstar
  • ******
  • Posts: 2619
  • Even when the bears bite, confidence never dies.
  • Respect: +16
Re: Families of functions question
« Reply #7 on: February 26, 2008, 11:05:56 pm »
0
lol, bloody hell why use my "alegbraic equality way". Urgh, it was an alternative.

Synthetic Division is always a winnar in these sort of questions.

EDIT: Found way. I'll type the alternative way soon. I SHOULD GET MY ENGLISH DONE :(
« Last Edit: February 26, 2008, 11:09:27 pm by AppleXY »

2009 - BBus (Econometrics/Economics&Fin) @ Monash


For Email: click here

Need a question answered? Merspi it!

[quote="Benjamin F

Toothpaste

  • pseudospastic
  • Victorian
  • Part of the furniture
  • *****
  • Posts: 1648
  • Member #10
  • Respect: +26
Re: Families of functions question
« Reply #8 on: February 26, 2008, 11:21:39 pm »
0
=
times through by 5x+3



To find A eliminate B:
let x =



 


now for B:


let x = 1
... (1)

let x = 0

rearrange
...(2)

sub (2) into (1):






=
put A and B back

=






... same as dcc's :D ... with partial fractions
« Last Edit: February 26, 2008, 11:35:06 pm by Toothpick »

humph

  • Victorian
  • Part of the furniture
  • *****
  • Posts: 1437
  • Respect: +16
Re: Families of functions question
« Reply #9 on: February 27, 2008, 11:30:49 am »
0
Hi all,

We have been given an assignment on Chapter 3: Families of functions (Essential Math Methods 3&4 textbook). I have been able to answer all questions on the assignment easily (the assignment is quite easy), apart from one of them. Any help is appreciated.

Express in the form

Thanks!
wow, i'd just do that kinda in my head...



i always just find it easier to manipulate the top line to match the bottom than to do long division or anything like that...
VCE 2006
PhB (Hons) (Sc), ANU, 2007-2010
MPhil, ANU, 2011-2012
PhD, Princeton, 2012-2017
Research Associate, University College London, 2017-2020
Assistant Professor, University of Virginia, 2020-

Feel free to ask me about (advanced) mathematics.

lanvins

  • Guest
Re: Families of functions question
« Reply #10 on: February 27, 2008, 04:00:29 pm »
0
for the way dcc did it, how did u get q(X) r(x)?

dcc

  • Victorian
  • Part of the furniture
  • *****
  • Posts: 1198
  • Respect: +55
  • School Grad Year: 2008
Re: Families of functions question
« Reply #11 on: February 27, 2008, 08:15:03 pm »
0
q(x) is like the quotient,  if you divide 12 by 4, 3 is the quotient.
r(x) is the remainder

AppleXY

  • Life cannot be Delta Hedged.
  • Victorian
  • ATAR Notes Superstar
  • ******
  • Posts: 2619
  • Even when the bears bite, confidence never dies.
  • Respect: +16
Re: Families of functions question
« Reply #12 on: February 27, 2008, 08:23:41 pm »
0
Mmm. In synthetic division (aka Long Div) if you divide q(x) with r(x) this results in partial fractions if the remainder is not 0 :) [if zero, this will be a  factor of q(x) ].

oh btw, when you obtain a remainder r(x) will be on the denominator.

i.e. + where Y is the constant.
« Last Edit: February 27, 2008, 08:30:30 pm by AppleXY »

2009 - BBus (Econometrics/Economics&Fin) @ Monash


For Email: click here

Need a question answered? Merspi it!

[quote="Benjamin F

Mao

  • CH41RMN
  • Honorary Moderator
  • Great Wonder of ATAR Notes
  • *******
  • Posts: 9181
  • Respect: +390
  • School: Kambrya College
  • School Grad Year: 2008
Re: Families of functions question
« Reply #13 on: February 27, 2008, 09:10:42 pm »
0
let me have a crack at solving it without long division:

in the form

therefore:





cross multiplying:







therefore:

[1]: , [2]: , [3]:

from [1]: ,

substituting into [2]:







and hence, substituting a and c gives:



yay i got the same as everyone else



.. :D
« Last Edit: February 27, 2008, 09:21:39 pm by Mao »
Editor for ATARNotes Chemistry study guides.

VCE 2008 | Monash BSc (Chem., Appl. Math.) 2009-2011 | UoM BScHon (Chem.) 2012 | UoM PhD (Chem.) 2013-2015

AppleXY

  • Life cannot be Delta Hedged.
  • Victorian
  • ATAR Notes Superstar
  • ******
  • Posts: 2619
  • Even when the bears bite, confidence never dies.
  • Respect: +16
Re: Families of functions question
« Reply #14 on: February 27, 2008, 09:38:49 pm »
0
lol, theres many ways to do. But I'd do the synthetic or equalities using >1 coffecients (toothpick's posts).



2009 - BBus (Econometrics/Economics&Fin) @ Monash


For Email: click here

Need a question answered? Merspi it!

[quote="Benjamin F