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

Qualification => Subject Doubts => GCE AS & A2 Level => Math => Topic started by: Igcseboy on April 22, 2010, 12:34:03 pm

Title: C1 edexcel doubts!!!
Post by: Igcseboy on April 22, 2010, 12:34:03 pm
I need urgent help i have my mocks on saturday and so i was practicing the past papers

please any1 help!!!

MAY 2005 Question 8 c
MAY 2006 11 d
JAN 2007 3
MAY 2007 5 and 11 c
JAN 2009 8 b (ii)
Title: Re: C1 edexcel doubts!!!
Post by: Amr Fouad on April 22, 2010, 12:37:12 pm
Give me some time
Title: Re: C1 edexcel doubts!!!
Post by: Igcseboy on April 22, 2010, 12:38:38 pm
Is 2 hrs enough???
Title: Re: C1 edexcel doubts!!!
Post by: Amr Fouad on April 22, 2010, 12:39:45 pm
MAY 2005 Question 8 c:

Area= 0.5 x base x height

base= OC = 7

Height= x-coordinate of P as its perpendicular to the base = 3

Therefore Area- 0.5 x base x height
Title: Re: C1 edexcel doubts!!!
Post by: Amr Fouad on April 22, 2010, 12:40:17 pm
Is 2 hrs enough???

lol no i already posted the 1st question :)
Title: Re: C1 edexcel doubts!!!
Post by: nid404 on April 22, 2010, 12:41:29 pm
I always have difficulty downloading edexcel papers...


Thanks AF :)
Title: Re: C1 edexcel doubts!!!
Post by: Amr Fouad on April 22, 2010, 12:43:44 pm
MAY 2006 11 d:

What's your problem with triangles lol :P ?

Anyways:

Area= 0.5 x base x height

height = RS = 2(50.5)

Base= PQ= (11+1)^2 1+ (8-2)^2 all square root

therefore area= 45 units of area
Title: Re: C1 edexcel doubts!!!
Post by: Amr Fouad on April 22, 2010, 12:44:38 pm
I always have difficulty downloading edexcel papers...


Thanks AF :)

No prblm nid..But why is that? Tried FEP?  :-\
Title: Re: C1 edexcel doubts!!!
Post by: nid404 on April 22, 2010, 12:46:25 pm
No prblm nid..But why is that? Tried FEP?  :-\

Yup...the thing is it's not named properly...I get confused as to which paper it is...sometimes im lucky enough to get

thanks...you're doing a great job
Title: Re: C1 edexcel doubts!!!
Post by: Igcseboy on April 22, 2010, 12:47:03 pm
in may 2005 11 d how is RS the ht..

Ya i have prb. with area of triangles in C1 :D
Title: Re: C1 edexcel doubts!!!
Post by: Amr Fouad on April 22, 2010, 12:50:04 pm
JAN 2007 3:

(a) All u've gotta do is to transform the y-coordinates 3 upwards....

Therefore, the x- asymptote doesnt change..

but the y-asymptote changes to +3 (0+3=3)

In other words, The whole graph shifts by +3 units upwards..x-coordinates dont change


(b) It crosses the x-axis when y=0:

(1/x)+3=0

(1/x)= -3

x= -1/3


It crosses the y-axis when x=0:

(1/0)+3 =y

It gives us math error, therefore it doesnt corss the y-axis

Therefore, only coordinates:

(-1/3, 0)
Title: Re: C1 edexcel doubts!!!
Post by: Amr Fouad on April 22, 2010, 12:51:19 pm
in may 2005 11 d how is RS the ht..

Ya i have prb. with area of triangles in C1 :D

RS is the height as it already told you its perpendicular to the base....got it?
Title: Re: C1 edexcel doubts!!!
Post by: Igcseboy on April 22, 2010, 12:53:29 pm
RS is the height as it already told you its perpendicular to the base....got it?


oh yes!!!! so the ht.. will always be the one perpendicular to the base?????
Title: Re: C1 edexcel doubts!!!
Post by: Amr Fouad on April 22, 2010, 12:55:49 pm
MAY 2007 5:

(a) We have to transofrmations..

1. Multiplying the whole function by 3-----> i.e. multiply the y-coordinates by 3-----> still no change in general shape of the curve..

2. +3 near x-----> i.e subtract 3 from x-coordinates ------> graph moves by 3 units to the left...

Asypmtotes:

y-asymptoe: 3x 0=0

x-asymptote: 0-3=-3

Finding coordinates:

Only with y-axis: put x=0:

therefore------> (0, 3/2)
Title: Re: C1 edexcel doubts!!!
Post by: Igcseboy on April 22, 2010, 12:56:15 pm
MAY 2005 Question 8 c:

Area= 0.5 x base x height

base= OC = 7

Height= x-coordinate of P as its perpendicular to the base = 3

Therefore Area- 0.5 x base x height


here it is not mentioned tht P is perpendicular???
Title: Re: C1 edexcel doubts!!!
Post by: Amr Fouad on April 22, 2010, 12:56:45 pm

oh yes!!!! so the ht.. will always be the one perpendicular to the base?????

Of course!! Its a must!
Title: Re: C1 edexcel doubts!!!
Post by: Amr Fouad on April 22, 2010, 12:58:02 pm

here it is not mentioned tht P is perpendicular???

Yes..but u have to use logic and common sense...the base is on the y-axis..Therefore ANY point with its x-coordinate will be perpendicular to it!
Title: Re: C1 edexcel doubts!!!
Post by: Igcseboy on April 22, 2010, 12:59:29 pm
Yes..but u have to use logic and common sense...the base is on the y-axis..Therefore ANY point with its x-coordinate will be perpendicular to it!

oh ya Thanks :)
Title: Re: C1 edexcel doubts!!!
Post by: Amr Fouad on April 22, 2010, 01:02:50 pm
JAN 2009 8 b (ii) :

As i said before:

y-intersections-----> put x=0:

(1)^2 (2-0)= 2 --------> (0,2)

x-intersections-----> put y=0:

x=-1, 2 --------) (-1,0) (-1,0) (2,0)

Then draw a cubic graph...since coefficient of x^3 <0 (when u expand the function), it will take the negative parabola form..

THATS IT! lol :P
Title: Re: C1 edexcel doubts!!!
Post by: Igcseboy on April 22, 2010, 01:03:29 pm
JAN 2009 10 d
JAN 2006 9
Title: Re: C1 edexcel doubts!!!
Post by: Amr Fouad on April 22, 2010, 01:12:31 pm
Sorry..I'm out now..When I go home  :-\
Title: Re: C1 edexcel doubts!!!
Post by: Igcseboy on April 22, 2010, 01:13:49 pm
ok..

Thanx Aloot