IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Math => Topic started by: EVIL DOCTOR on January 10, 2010, 05:35:52 pm

Title: c1 help plzzzzzzzzzzzz
Post by: EVIL DOCTOR on January 10, 2010, 05:35:52 pm

how can u know the coordinates that crosses the x-axis as quick as possible :

Y= (x-2)^3 - 6(x-2)^2 + 9(x-2)

Title: Re: c1 help plzzzzzzzzzzzz
Post by: XFlufferzX on January 10, 2010, 05:45:18 pm

Y= (x-2)^3 - 6(x-2)^2 + 9(x-2)

solve for x

1) x = 2

2) -6x + 12
     x = 2

3) 9x - 18
     x = 2

wow all of 'em are 2 .___.
are my answers correct? :S

from where did yuh get this problem? is it from the past paper?

Title: Re: c1 help plzzzzzzzzzzzz
Post by: EVIL DOCTOR on January 10, 2010, 05:48:35 pm

thats wrong!!! 
 yes its from pastpapers!!!!!!!!!!!!!

Title: Re: c1 help plzzzzzzzzzzzz
Post by: XFlufferzX on January 10, 2010, 05:50:34 pm

Oh mannnnn
which year is it? xD

Title: Re: c1 help plzzzzzzzzzzzz
Post by: XFlufferzX on January 10, 2010, 05:55:54 pm

oh its june 2009 >_< havent solved it yet

Title: Re: c1 help plzzzzzzzzzzzz
Post by: T.Q on January 10, 2010, 05:56:53 pm

Quote from: EVIL DOCTOR on January 10, 2010, 05:35:52 pm

how can u know the coordinates that crosses the x-axis as quick as possible :

Y= (x-2)^3 - 6(x-2)^2 + 9(x-2)

take (x-2) as a common factor
 
(x-2)( (x-2)^2-6(x-2)+9 )
 
make y=(x-2)

so the equation will be like this

y(y^2-6y+9)

factorise

then...

y=0
y=3

which means
x-2=0   and   x-2=3

x=2 or x=5
 

Title: Re: c1 help plzzzzzzzzzzzz
Post by: XFlufferzX on January 10, 2010, 05:59:36 pm

Quote

take (x-2) as a common factor
 
(x-2)( (x-2)^2-6(x-2)+9 )
 
make y=(x-2)

so the equation will be like this

y(y^2-6y+9)

factorise

then...

y=0
y=3

which means
x-2=0   and   x-2=3

x=2 or x=5

Awesooooome now I get it!  :D thx

Title: Re: c1 help plzzzzzzzzzzzz
Post by: rreizend on January 10, 2010, 06:12:25 pm

this is a horizontal translation f(x-2) where f(x)=x^3-6x^2+9x from the previous question

since its f(x-2) then you hav to add 2 to all x points. ;D

its simple really :D

Title: Re: c1 help plzzzzzzzzzzzz
Post by: XFlufferzX on January 10, 2010, 06:34:05 pm

Quote

this is a horizontal translation f(x-2) where f(x)=x^3-6x^2+9x from the previous question

since its f(x-2) then you hav to add 2 to all x points.

Lol riight!

Title: Re: c1 help plzzzzzzzzzzzz
Post by: Ghost Of Highbury on January 11, 2010, 09:22:56 am

wats the full form of C1..??

Title: Re: c1 help plzzzzzzzzzzzz
Post by: astarmathsandphysics on January 11, 2010, 11:04:05 am

wats the full form of C1..??

I dont understand

Title: Re: c1 help plzzzzzzzzzzzz
Post by: rreizend on January 11, 2010, 12:19:03 pm

you mean as in Core Meathematics 1 ? ???

Title: Re: c1 help plzzzzzzzzzzzz
Post by: Dreams <3 on January 11, 2010, 04:04:33 pm

Quote from: A@di on January 11, 2010, 09:22:56 am

wats the full form of C1..??

Edexcel AS GCE
Core Mathematics 1  (6663)