Author Topic: [CIE] All Pure Mathematics (P1, P2 and P3) doubts here !  (Read 79936 times)

Offline Aadeez || Zafar

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Re: All Pure Mathematics DOUBTS HERE!!!
« Reply #165 on: April 16, 2011, 07:29:16 pm »
MJ 2004 Q10 part one,i was always wondering why do you have to change the sign of the least value,anyone knows that?
give me the link of the question paper



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Re: All Pure Mathematics DOUBTS HERE!!!
« Reply #166 on: April 17, 2011, 05:00:24 am »
MJ 2004 Q10 part one,i was always wondering why do you have to change the sign of the least value,anyone knows that?

x2 -2x >15

Hence,  x2 -2x -15 > 0

Solving this gives the two critical values :

x = -3 and x = 5

Sketching a parabola with these values (see below).

Since the inequality states that x must be GREATER than zero we are only interested in x-coordinates that meet the red part of the parabola.

Hence, x<-3 , x>5

Offline thecandydoll

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Re: All Pure Mathematics DOUBTS HERE!!!
« Reply #167 on: April 17, 2011, 05:43:36 am »
7With respect to the origin O, the points A and B have position vectors given by OA = i + 2j + 2k and
 OB = 3i + 4j. The point P lies on the line AB and OP is perpendicular to AB.
(i) Find a vector equation for the line AB.   [1]
(ii) Find the position vector of P.   [4]
(iii) Find the equation of the plane which contains AB and which is perpendicular to the plane OAB, giving your answer in the form ax + by + c???? = d.

i dont get the second part

Offline HUSH1994

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Re: All Pure Mathematics DOUBTS HERE!!!
« Reply #168 on: April 17, 2011, 12:54:21 pm »
Thanks man you really fit for a teacher ;)

Offline Chingoo

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Re: All Pure Mathematics DOUBTS HERE!!!
« Reply #169 on: April 21, 2011, 05:33:27 pm »
Could someone solve P31 May June 10 Q1 GRAPHICALLY? Thanks on advance to whoever does me the great favor! ;D
« Last Edit: April 21, 2011, 05:35:16 pm by Chingoo »
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Offline EMO123

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Re: All Pure Mathematics DOUBTS HERE!!!
« Reply #170 on: April 22, 2011, 04:19:02 pm »
you may think that am i gone crazzy or what but
can you tell me is 2 a prime number or not
and is 1 a prime number ??? :'(

it is very simple to say this to me so any one faster as much as you can

Offline HUSH1994

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Re: All Pure Mathematics DOUBTS HERE!!!
« Reply #171 on: April 22, 2011, 04:26:21 pm »
yeah 1 & 2 are prime numbers

Offline EMO123

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Re: All Pure Mathematics DOUBTS HERE!!!
« Reply #172 on: April 22, 2011, 04:27:26 pm »
yeah 1 & 2 are prime numbers
thanx friend but i am just stupid for a while
but now it's clear thanx friend

Offline HUSH1994

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Re: All Pure Mathematics DOUBTS HERE!!!
« Reply #173 on: April 22, 2011, 04:30:51 pm »
anytime ;)

Offline EMO123

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Re: All Pure Mathematics DOUBTS HERE!!!
« Reply #174 on: April 22, 2011, 04:46:12 pm »
paper 1
8709/1/o/n/01
Question No. 3

elemis

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Re: All Pure Mathematics DOUBTS HERE!!!
« Reply #175 on: April 23, 2011, 05:28:18 am »
paper 1
8709/1/o/n/01
Question No. 3


The inverse function of y=cosx is     x = cos-1y

x = cos-1y has a range of 0 to pi.

Since the range of the inverse function is the domain of the normal function :

k = pi

Offline EMO123

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Re: All Pure Mathematics DOUBTS HERE!!!
« Reply #176 on: April 23, 2011, 12:54:17 pm »
The inverse function of y=cosx is     x = cos-1y

x = cos-1y has a range of 0 to pi.

Since the range of the inverse function is the domain of the normal function :

k = pi

thanxx ari

Offline m.bhaiyat

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Re: All Pure Mathematics DOUBTS HERE!!!
« Reply #177 on: April 25, 2011, 08:02:02 pm »
hey guys..need help on may june 2009 questions 1,3(ii), and 4.
thanks

Offline astarmathsandphysics

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Re: All Pure Mathematics DOUBTS HERE!!!
« Reply #178 on: April 25, 2011, 09:23:46 pm »
hey guys..need help on may june 2009 questions 1,3(ii), and 4.

 see attachment

Offline SkyPilotage

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Re: All Pure Mathematics DOUBTS HERE!!!
« Reply #179 on: April 26, 2011, 08:44:04 pm »
I rlly dont know how to explain math on computer...
On question number 1, its always better to make 2 fraactions into a single fraction. Here you will have in the denominator (1+sinx)(1-sinx)=(1-sin^2x)=cos^2x
and the numerator would be sinx(1+sinx)-sinx(1-sinx)=sinx+sin^2x-sinx+sin^2x=2sin^x
There you go 2tan^x.
Question 3 ii)
you will multiplay ax by the "x" in the other brackets and multiplay 1 by the x^2 term in the other brackets. Their sum must be equal to zero!
Question 4 i)
-substitue x=0 y=3 ---->c=3
-ok now the maximum value for any sin function is 1 and minimum is -1. same thing for cosine.
so when y=9 sinbx=1 so a=6
-hmm now when u have sin(2x) the x values of sinx are divided by 2. so its as if its compressed by two. Look at the graphs of sin2x and sinx and compare. Maybe someone could have a better explanation for this last part.