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

Qualification => Subject Doubts => GCE AS & A2 Level => Math => Topic started by: halosh92 on December 03, 2009, 08:09:10 pm

Title: math C1 doubt
Post by: halosh92 on December 03, 2009, 08:09:10 pm
  hello , its a silly 1 mark question but i just dont get it:
maths edexcel
C1
2008 JAN
Q6 part c


and one more question:
 2008 jan
Q 7 part d
Title: Re: math C1 doubt
Post by: staceyboy3 on December 04, 2009, 05:19:49 am
 hello , its a silly 1 mark question but i just dont get it:
maths edexcel
C1
2008 JAN
Q6 part c


and one more question:
 2008 jan
Q 7 part d

Where do you get edexcel past papers? I wanna see the question :)
Title: Re: math C1 doubt
Post by: vanibharutham on December 04, 2009, 06:47:48 am
The maximum point on the curve with equation y = f(x + a) is on the y-axis.
(c) Write down the value of the constant a.

You can see that the maximum point on f(x) is at (2,5)
However, the question states that the maximum value of f(x+a) is on the y-axis, so we need to apply some transformation to f(x) to allow it to reach the y-axis...

Quite simply, a = 2

because f(x+2) moves f(x) 2 units to the left

and hence the maximum will be on (0,5) which is on the y axis :)
Title: Re: math C1 doubt
Post by: vanibharutham on December 04, 2009, 06:51:24 am
(d) write down the value of x2008.

First thing, dont freak out if u see some huge number like that, because thats exactly what they want u to do, but there is a trick.

From part (c) you should have deduced that p = -1.5

Now the way i would do this is as follows:

Using the iterative formula, i would x2, x3, x4 and so on

Hence,

x1 = 1 (given)
x2 = -0.5
x3 = 1 (given)
x4 = -0.5

See the pattern?

All evens are -0.5
and all odds are 1

Hence, x2008 = -0.5

:)
Title: Re: math C1 doubt
Post by: halosh92 on December 04, 2009, 07:05:23 am
(d) write down the value of x2008.

First thing, dont freak out if u see some huge number like that, because thats exactly what they want u to do, but there is a trick.

From part (c) you should have deduced that p = -1.5

Now the way i would do this is as follows:

Using the iterative formula, i would x2, x3, x4 and so on

Hence,

x1 = 1 (given)
x2 = -0.5
x3 = 1 (given)
x4 = -0.5

See the pattern?

All evens are -0.5
and all odds are 1

Hence, x2008 = -0.5

:)


 thankx alot that was very gd,
but ummm i have one question, i never took this formula :"iterative formula"
do we always multiple by1, 2, 3, 4 in all cases ????
Title: Re: math C1 doubt
Post by: halosh92 on December 04, 2009, 07:07:12 am
Where do you get edexcel past papers? I wanna see the question :)

 i downloaded al myl pastpapers from freetextbooks.com
it comes as a whole package with all papers, the more the marrier  :P
Title: Re: math C1 doubt
Post by: vanibharutham on December 04, 2009, 07:41:13 am
The iterative formula was given to us :)

xn+1= xn(p +xn)

when n = 0, we get a value for x1 = 1 (given)
when n = 1, we get a value for x2 => x1(p + x1)
                                           ==> p + 1
when n = 2, we get a value for x3 => x2(p + x2)
                                           ==> (p+1)( p + p + 1)
                                           ==> ( p + 1 ) ( 2p + 1 ) => 2p²+3p+1
and so on

and we found a value for p = -1.5

now , using that value

we can find
x1 = 1
x2 = -1.5 + 1 => -0.5
x3 = 1
x4 = -0.5
Title: Re: math C1 doubt
Post by: halosh92 on December 04, 2009, 07:44:43 am
The iterative formula was given to us :)

xn+1= xn(p +xn)

when n = 0, we get a value for x1 = 1 (given)
when n = 1, we get a value for x2 => x1(p + x1)
                                           ==> p + 1
when n = 2, we get a value for x3 => x2(p + x2)
                                           ==> (p+1)( p + p + 1)
                                           ==> ( p + 1 ) ( 2p + 1 ) => 2p²+3p+1
and so on
 
and we found a value for p = -1.5

now , using that value

we can find
x1 = 1
x2 = -1.5 + 1 => -0.5
x3 = 1
x4 = -0.5

 thankyou!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ;D ;D ;D ;D ;D
Title: Re: math C1 doubt
Post by: astarmathsandphysics on December 04, 2009, 08:34:58 am
Please seed
Title: Re: math C1 doubt
Post by: staceyboy3 on December 04, 2009, 03:12:04 pm
i downloaded al myl pastpapers from freetextbooks.com
it comes as a whole package with all papers, the more the marrier  :P

Wow thanks! :)

Useful site, thanks again ;D
Title: Re: math C1 doubt
Post by: astarmathsandphysics on December 04, 2009, 03:21:14 pm
Thousands of papers with a few clicks and textbooks too but please seed.
Title: Re: math C1 doubt
Post by: halosh92 on December 04, 2009, 03:22:01 pm
Thousands of papers with a few clicks and textbooks too but please seed.

am new here, how do we exactly seed????
Title: Re: math C1 doubt
Post by: Blood0cean on December 04, 2009, 03:44:57 pm
this got nothing to do with the topic but im doing a levels CIE and i cant find any CIE passpapers online for statistics..
its really bumming me out . If some 1 has an answer to that id apperitiate it if u helped.

Im doing 1st year A levels Math.
im gonna be doing Pure math paper 1 and Statistics paper 1
S1 P1
 :-X
Title: Re: math C1 doubt
Post by: astarmathsandphysics on December 04, 2009, 04:02:07 pm
Def some on freeexampapers
Title: Re: math C1 doubt
Post by: halosh92 on December 04, 2009, 04:31:27 pm
this got nothing to do with the topic but im doing a levels CIE and i cant find any CIE passpapers online for statistics..
its really bumming me out . If some 1 has an answer to that id apperitiate it if u helped.

Im doing 1st year A levels Math.
im gonna be doing Pure math paper 1 and Statistics paper 1
S1 P1
 :-X

i only have edexcel for these papers ..u want them??
Title: Re: math C1 doubt
Post by: staceyboy3 on December 04, 2009, 04:36:30 pm
am new here, how do we exactly seed????

You use some sort of bittorent client, right? :) After you download something, you simply leave it alone. In the client it should have a green arrow pointing up next to the download. Leaving the client open will seed the downloaded content, so that in a sense you upload it to someone else who is downloading... :)

This is how torrents work, by sharing files and helping others download them.
Title: Re: math C1 doubt
Post by: halosh92 on December 04, 2009, 04:40:42 pm
You use some sort of bittorent client, right? :) After you download something, you simply leave it alone. In the client it should have a green arrow pointing up next to the download. Leaving the client open will seed the downloaded content, so that in a sense you upload it to someone else who is downloading... :)

This is how torrents work, by sharing files and helping others download them.
okek ill try doing that now thx!! ;D
Title: Re: math C1 doubt
Post by: astarmathsandphysics on December 04, 2009, 05:09:28 pm
utorrent is the best.
Title: Re: math C1 doubt
Post by: staceyboy3 on December 04, 2009, 05:59:41 pm
utorrent is the best.

Agreed :)
Title: Re: math C1 doubt
Post by: halosh92 on December 04, 2009, 06:05:53 pm
utorrent is the best.

 me agree 2 its rili awesome!!!!