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

Qualification => Subject Doubts => GCE AS & A2 Level => Math => Topic started by: thecandydoll on September 18, 2010, 02:48:06 pm

Title: Cie math P1
Post by: thecandydoll on September 18, 2010, 02:48:06 pm
Paper 1 Pure math !
Summer :May/JUNE 2010
Paper 12.
Question 11,How do solve the whole thing I dont get it :(
Title: Re: Cie math P1
Post by: elemis on September 18, 2010, 02:57:52 pm
Okay. Hang on.
Title: Re: Cie math P1
Post by: elemis on September 18, 2010, 03:04:29 pm
(i) 4-3sinx = 2

Hence, 4-2=3sinx  I re-arranged the equation

2/3 = sinx 

sin-1 2/3 = 41.8, 138.2 degrees

Converting to radians gives: 0.730 and 2.41 respectively.
Title: Re: Cie math P1
Post by: elemis on September 18, 2010, 03:25:31 pm
(ii) Basically you reflect a regular sine graph in the x axis. Then multiply each Y coordinate by 3.

After that vertically move the graph by 4 units.
Title: Re: Cie math P1
Post by: elemis on September 18, 2010, 03:35:32 pm
(iii)

Basically they are asking you to find the range of y coordinates for which the Sine Graph has no x values.

Looking at my picture we can see that the graph has no point below the y coordinate of 1 or above the y coordinate of 7.

Hence k > 7 , k < 1
Title: Re: Cie math P1
Post by: elemis on September 18, 2010, 03:36:31 pm
I dont know the others :P
Title: Re: Cie math P1
Post by: Freaked12 on September 18, 2010, 04:36:31 pm
Ah we meet again Lioness  :P

If a function is to have inverse,it must be one - one function.The graph of such function can only be crossed by a line parallel to the x axis once only .

As our Lioness Ari drew in his Graph the highest value by  which the graph is parallel to x axis is 3/2 pi
Title: Re: Cie math P1
Post by: elemis on September 18, 2010, 04:45:24 pm
Ah we meet again Lioness  :P

If a function is to have inverse,it must be one - one function.The graph of such function can only be crossed by a line parallel to the x axis once only .

As our Lioness Ari drew in his Graph the highest value by  which the graph is parallel to x axis is 3/2 pi

Subconsciously you know I am a male. Your just a scatter brain. :P
Title: Re: Cie math P1
Post by: Freaked12 on September 18, 2010, 04:51:04 pm
Sub consciously or consciously I Doubt you are a Lion at all.

Maybe a Cub but thats about it.

Meet the Rogue Lion that will in time kill the heard's leader and finish off the cubs.  :-\

I am so Jobless today  :-\
Title: Re: Cie math P1
Post by: Aadeez || Zafar on September 18, 2010, 04:59:43 pm
u both can just stop fighting with arguments as ur wepons
Title: Re: Cie math P1
Post by: elemis on September 18, 2010, 05:01:48 pm
Sub consciously or consciously I Doubt you are a Lion at all.

Maybe a Cub but thats about it.

Meet the Rogue Lion that will in time kill the heard's leader and finish off the cubs.  :-\

I am so Jobless today  :-\

You sound drunk...
Title: Re: Cie math P1
Post by: S.M.A.T on September 18, 2010, 07:17:36 pm
Here :)
Title: Re: Cie math P1
Post by: Freaked12 on September 18, 2010, 09:16:36 pm
Give +rep to me yeah.i am dieing to get a rep
Title: Re: Cie math P1
Post by: Aadeez || Zafar on September 19, 2010, 05:45:56 am
rep r not asked for
they r given if any users want
so dont force them to give +rep
Title: Re: Cie math P1
Post by: nid404 on September 19, 2010, 08:04:37 am
Give +rep to me yeah.i am dieing to get a rep

Do not ask for rep...against the rules  ::)
Title: Re: Cie math P1
Post by: Freaked12 on September 19, 2010, 10:51:46 am
I am bored :/
Title: Re: Cie math P1
Post by: Alpha on September 19, 2010, 11:06:06 am
Find a teacher to give you some homework. ;)
Title: Re: Cie math P1
Post by: missbeautiful789 on October 11, 2010, 10:23:49 pm
The answer isn't 0.34

it's 2.80....check the marking scheme (attached)

Why did they say pi-0.34..uh?
How?
Title: Re: Cie math P1
Post by: S.M.A.T on October 11, 2010, 11:13:33 pm
The answer isn't 0.34

it's 2.80....check the marking scheme (attached)

Why did they say pi-0.34..uh?
How?

O thanks for finding my error  :D +rep
In the question it says the domain is 0.5pi<x<1.5pi(A).
o.34 is not within this domain so the answer is pi-0.34.

i modified my post :)
Title: Re: Cie math P1
Post by: Dania on October 12, 2010, 12:29:31 am
Asif, I need you again. :)

How would I find the inverse of this y= 2x2-12x+13

Thanks :D
Title: Re: Cie math P1
Post by: Deadly_king on October 12, 2010, 05:08:30 am
Asif, I need you again. :)

How would I find the inverse of this y= 2x2-12x+13

Thanks :D

Let f(x) = 2x2 - 12x + 13
First you should complete the square of the equation.

You'll obtain f(x) = 2(x-3)2 - 5

To obtain its inverse, you need to make x subject of formula.

Let 2(x-3)2 - 5 = y
y + 5 = 2(x-3)2 ----> (y + 5)/2 = (x-3)2
Now you take roots on both sides.
((y+5)/2)1/2 = x - 3
Hence x = ((y+5)/2)1/2 + 3
Now replace y by x

f-1(x) = ((x+5)/2)1/2 + 3
Therefore the inverse of the given equation will be ((x+5)/2)1/2 + 3

Hope it helps :)
Title: Re: Cie math P1
Post by: S.M.A.T on October 12, 2010, 09:35:06 pm
DK your workings will definitely help ;)........+rep
Title: Re: Cie math P1
Post by: Deadly_king on October 13, 2010, 11:53:24 am
DK your workings will definitely help ;)........+rep

Thanks buddy  :)