Parametrics (1 Viewer)

*zara*

zozo2nv
Joined
Oct 22, 2004
Messages
26
Location
sydney australia!!!
Gender
Undisclosed
HSC
N/A
i need serious help with parametrics we've juz finished the topic and i dont undestand it at all the Q 'z are so long and i hate the way they word them it confuses me badly so for anyone whosz got tips out dere that can help me start to see the big picture plz i need it!!!!!!!!!!!!!!!!!!!
tannx
 

mojako

Active Member
Joined
Mar 27, 2004
Messages
1,333
Gender
Male
HSC
2004
Big picture:
You're trying to combine two equations into one.
You use techniques such as substitution or addition of the two equations.

Example:
x=2at --(1)
y=at<sup>2</sup> --(2)
Express y in terms of x.
From (1) you have t=x/2a
Substitute this into (2):
y=a(x/2a)<sup>2</sup>
then just simplify / rearrange
 

Xayma

Lacking creativity
Joined
Sep 6, 2003
Messages
5,953
Gender
Undisclosed
HSC
N/A
Well you have to be able to derive all formula so you do not need to memorise them. They will (from all past papers I've seen) either get you to derive it or give it to you saying you do not need to prove it.
 

acmilan

I'll stab ya
Joined
May 24, 2004
Messages
3,989
Location
Jumanji
Gender
Male
HSC
N/A
Deriving the equations of normals, tangents etc usually are worth 1-2 marks and sometimes given. Normally they might ask in one section to find the x and y coordinates of a point, sometimes you can use these in finding the locus.
 

mojako

Active Member
Joined
Mar 27, 2004
Messages
1,333
Gender
Male
HSC
2004
u need to know the standard cartesian form of a parabola.
u need to know the standard parametric form of a parabola (just in case.. normally they give it to you)
u need to know that for focal chord PQ, pq=-1
 

wrong_turn

the chosen one
Joined
Sep 18, 2004
Messages
3,664
Location
Sydney
Gender
Male
HSC
2005
Uni Grad
2010
my textbook is far too hard. like the teacher taught us the basics, then we went right into the heart of the topic.

we have the fitzpatrick book though.
 

acmilan

I'll stab ya
Joined
May 24, 2004
Messages
3,989
Location
Jumanji
Gender
Male
HSC
N/A
The beginning part of Fitzpatrick is not overly difficult, its not until the end that some questions become a bit obscure
 

wrong_turn

the chosen one
Joined
Sep 18, 2004
Messages
3,664
Location
Sydney
Gender
Male
HSC
2005
Uni Grad
2010
acmilan said:
The beginning part of Fitzpatrick is not overly difficult, its not until the end that some questions become a bit obscure
look at the problem solving for 24(c). we got flung into it right after we did the theory?!
 

*zara*

zozo2nv
Joined
Oct 22, 2004
Messages
26
Location
sydney australia!!!
Gender
Undisclosed
HSC
N/A
thanx everyone...... wat i done was made my self sit down for 2 hours straight and tried to tyeach myself the basics then i started to understand it much more clearly and i found it pretty interesting until it got alot harder so i got a tutor and shes exellent better than my teacher and so im half way thru and understand it till now !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! its all good
thanx again
 

currysauce

Actuary in the making
Joined
Aug 31, 2004
Messages
576
Location
Sydney
Gender
Male
HSC
2005
i actually don't mind parametrics, + locus and parabolas (yr 12)... at first i hated them... but after about a week of full practice meh.... wat i do hate is all the formulas... such as normals intersect at such and such... lol...

but if u need help just pm me...
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top