Author Topic: IGCSE MATHS Doubts  (Read 120726 times)

Offline Fastal

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Re: IGCSE MATHS Doubts
« Reply #435 on: May 11, 2010, 06:20:34 pm »

Offline Malak

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Re: IGCSE MATHS Doubts
« Reply #436 on: May 11, 2010, 06:21:59 pm »
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Offline Shazizzzle

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Re: IGCSE MATHS Doubts
« Reply #437 on: May 11, 2010, 06:24:07 pm »
can you tell me why please??

DCA = DAT (Alternate Segment Theory)

If DAO = 32, DAT = 90 - 32 = 58.

So, DCA = 58. :)
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Offline Dibss

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Re: IGCSE MATHS Doubts
« Reply #438 on: May 11, 2010, 06:25:57 pm »
Quote
58

can you tell me why please??

hey, I'm assuming you know the alternate segment theorem which says the angle between a tangent and a chord drawn form the point of contact is equal to any angle in the alternate segment.
in your qs, DAT will be equal to any angle subtended by line AD in the opposite segment. therefore angle DAT=ACD=58 :]
« Last Edit: May 11, 2010, 06:36:11 pm by Dibss »

Offline Shazizzzle

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Re: IGCSE MATHS Doubts
« Reply #439 on: May 11, 2010, 06:28:17 pm »
Nov 09 Q 4 & 14 http://www.freeexampapers.us/IGCSE/Maths/CIE/2009%20Nov/0580_w09_qp_22.pdf

Thx alot

Umm, separate the coeffecients from the variables.

i.e First do 5/8 /  1/2
=5/8 X 2/1 (reciprocal of 1/2 taken when introducing multiplication)
=10/8
1/1/4.

Then the variables.

x^3/2  /  x^-5/2
=x^ 3/2 - (-5/2)
=x^3/2+5/2
=x^8/2
=x^4

So, Answer: 1/1/4x^4 :)

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Offline Dark Prince

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Re: IGCSE MATHS Doubts
« Reply #440 on: May 11, 2010, 06:29:19 pm »
its vertically left.

Sorry to ask this again......but i still dont get it hoe is it moving to left...thnkx

Offline Fastal

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Re: IGCSE MATHS Doubts
« Reply #441 on: May 11, 2010, 06:30:16 pm »
hey, I'm assuming you know the alternate segment theorem which says the angle between a tangent and a chord drawn form the point of contact is equal to any segment in the alternate segment.
in your qs, DAT will be equal to any angle subtended by line AD in the opposite segment. therefore angle DAT=ACD=58 :]

Thank You

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Offline Dibss

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Re: IGCSE MATHS Doubts
« Reply #442 on: May 11, 2010, 06:32:39 pm »
Quote
Nov 09 Q 4 & 14 http://www.freeexampapers.us/IGCSE/Maths/CIE/2009%20Nov/0580_w09_qp_22.pdf

Thx alot
14:
P(1+R/100)^T
249(1+1.7/100)3
=261.92
Interest =261.92-249 =12.92

Fastal, you're welcome :]

Offline Fastal

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Re: IGCSE MATHS Doubts
« Reply #443 on: May 11, 2010, 06:33:34 pm »
Sorry to ask this again......but i still dont get it hoe is it moving to left...thnkx


i dont get it either :(

Offline haris94

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Re: IGCSE MATHS Doubts
« Reply #444 on: May 11, 2010, 06:35:07 pm »
Nov 09 Q 4 & 14 http://www.freeexampapers.us/IGCSE/Maths/CIE/2009%20Nov/0580_w09_qp_22.pdf

Thx alot

Q 4)  whenever it is division, u hv to subtract the powers
so 3/2 - (-5/2) = 4
and (5/8)/(1/2) is equal to 5/4 or 1.25

so answer is 1.25x4
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Offline haris94

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Re: IGCSE MATHS Doubts
« Reply #445 on: May 11, 2010, 06:39:27 pm »
Nov 09 Q 4 & 14 http://www.freeexampapers.us/IGCSE/Maths/CIE/2009%20Nov/0580_w09_qp_22.pdf

Thx alot

Q 14)
A = P(1+r/100)n

A = 249(1+1.7/100)3

A = $261.92

interest = A-P
261.92-249
$12.92
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Offline haris94

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Re: IGCSE MATHS Doubts
« Reply #446 on: May 11, 2010, 06:46:01 pm »

i dont get it either :(

from the x-axis u need to move -1 to reach the triangle

this is what i think
if from the x-axis u need to move left, then factor is in -ve
if u move right, factor will be a +ve number
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Offline 33oomar

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Re: IGCSE MATHS Doubts
« Reply #447 on: May 11, 2010, 06:53:01 pm »
what is the rule for compound intrest please no symbols full words

Offline Shazizzzle

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Re: IGCSE MATHS Doubts
« Reply #448 on: May 11, 2010, 06:54:16 pm »
from the x-axis u need to move -1 to reach the triangle

this is what i think
if from the x-axis u need to move left, then factor is in -ve
if u move right, factor will be a +ve number

This is all crap.

It's clear that if y-axis is the invariant line, up (right, if y-axis is brought horizontal) is +ve, down is negative.
If the x-axis is the invariant line, right is positive and left negative.

People say it's related to the quadrant the shear was in.

The only explanation is that CIE made a mistake and was too lame to admit it, even in the ER, therefore defended the answers WITHOUT GIVING A CLEAR EXPLANATION TO WHY IT WAS -ve.

Also, the principal examiner, has expressed how he would like to reduce graph and transformation questions as they are easy, and replace them with difficult investigating, sequence and probability questions.

As transformation showed up in Nov 2009, is it unlikely to show up this year.

Also, that question was from Paper 4.
We've got Paper 2 tomorrow. Chillax. :)
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Offline The Hitman

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Re: IGCSE MATHS Doubts
« Reply #449 on: May 11, 2010, 06:56:52 pm »
There's something called Google.com :)
...
...
...
LMAO!
*sings google is your friend*
I have this nasty habit of trusting people.