Mathematics: Post your doubts here!

[tweetie]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s12_qp_42.pdf
q-4 i nd ii pls help

 

[notnek01]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s12_qp_42.pdf
q-4 i nd ii pls help

Do you mean 4ai and 4aii ?

 

[tweetie]

no 4c i nd ii nd 7 b iv pls help

 

[notnek01]

no 4c i nd ii nd 7 b iv pls help

4ci:

1. CD = AD (they are both sides of the same square)
2. DG = DE (they are both sides of the same square)

<CDG = <ADG + 90
<ADE = <ADG + 90

3. So <CDG = <ADE.


cii:

Two corresponding sides and their included angle are equal (SAS) so triangles ADE and CDG are congruent.


7biv:

OE : ED = 2 : 1 --> O->D = 3/2 O->E

C->D = C->O + O->D = -c + 3/2 O->E

 

[arsenal4ever]

Guys,

I don't understand how to make the equation for the nth term?

Especially the hard ones, where you have to use square and cube..

 

[notnek01]

Guys,

I don't understand how to make the equation for the nth term?

Especially the hard ones, where you have to use square and cube..

You only need to know the method for arithmetic sequences where the nth term is of the form: an + b. (Can you do these?)

The nth terms of sequences involving squares and cubes can be found by 'recognising' the sequence or by using other sequences

Can you tell me a past paper question that you're struggling with?

 

[AmazynGal]

How to solve the inequalities using the graph?? Any Help?? the question about it is on Oct/Nov 2009 Question 6

 

[notnek01]

How to solve the inequalities using the graph?? Any Help?? the question about it is on Oct/Nov 2009 Question 6

Do you mean Paper 4, Question biii? In future, please say exactly which paper and which question part you need help with.

If f(x)<g(x) in a range a<x<b, it means that between a and b, the graph of f(x) is below the graph of g(x).
If f(x)>g(x), it means that the graph of f(x) is above the graph of g(x).

Does this help?

 

[notnek01]

If you require CIE IGCSE Extended Maths revision notes (inc. questions/answers), please email me at [email protected]

I'm looking to get feedback and for people to find errors/typos.

 

[lordIceAndFire]

can someone help me on question no 10 and 11
http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s08_qp_2.pdf

 

[notnek01]

can someone help me on question no 10 and 11
http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s08_qp_2.pdf

10) 'The glass can be filled with water from the jar exactly 216 times.' This means that the volume of the jar is 216 times the volume of the glass i.e. the volume scale factor = 216.

Length scale factor = cube root ( Volume scale factor) = cube root ( 216 ) = 6.

Can you finish it from here?


11) You need to use the cosine rule:

21^2 = x^2 + (2x)^2 - 2(x)(2x) cos(120)

--> 21^2 = 5x^2 - 4x^2 (-0.5)

Can you solve the equation from here?

 

[lordIceAndFire]

10) 'The glass can be filled with water from the jar exactly 216 times.' This means that the volume of the jar is 216 times the volume of the glass i.e. the volume scale factor = 216.

Length scale factor = cube root ( Volume scale factor) = cube root ( 216 ) = 6.

Can you finish it from here?


11) You need to use the cosine rule:

21^2 = x^2 + (2x)^2 - 2(x)(2x) cos(120)

--> 21^2 = 5x^2 - 4x^2 (-0.5)

Can you solve the equation from here?

ahh..thanks!

 

[Heba Muneer]

Does anybody have an idea of where I can find the overall threshold for mathematics before June 2011? And do I always have to score above 175 to guarantee achieving an A* ?

 

[fbyfbyfby]

y ıs ınversly proportıonal to x^2
when X=4 Y=3
find y when x =5

 

[notnek01]

Does anybody have an idea of where I can find the overall threshold for mathematics before June 2011? And do I always have to score above 175 to guarantee achieving an A* ?

I don't think they were every released, sorry.

You don't always need over 175. E.g. Summer 12 21/41, 173=A*. Winter 12 23/43, 167 = A*.

 

[fbyfbyfby]

AsSalamoAlaikum Wr Wb...

Stuck somewhere in Maths?? Post your queries here! Members around will help you InshaAllah.

NOTE: If you have any doubt in the pastpper questions, then kindly post the link to the paper!

May Allah give us all success in this world as well as the HereAfter...Aameen!!

SEQUENCES-Points to remember:
Many people find it hard, but to be honest it's just more of logic..that's all!

Sequences!

Using log for indices.

y ıs ınversly proportıonal to x^2
when X=4 Y=3
find y when x =5

 

[notnek01]

y ıs ınversly proportıonal to x^2
when X=4 Y=3
find y when x =5

This is a very standard (inverse) proportion question - they're always very similar so you need to get used to the method:

y is inversely proportional to x^2 --> y ∝ 1/x^2 --> y = k/x^2

When x=4, y=4 so substitute this into the above equation to find k:

3 = k/4^2 --> k = 16 x 3 = 48.

Now putting this value for k into the equation:

y = 48/x^2

Find y when x=5. Can you do this now?

 

[fbyfbyfby]

This is a very standard (inverse) proportion question - they're always very similar so you need to get used to the method:

y is inversely proportional to x^2 --> y ∝ 1/x^2 --> y = k/x^2

When x=4, y=4 so substitute this into the above equation to find k:

3 = k/4^2 --> k = 16 x 3 = 48.

Now putting this value for k into the equation:

y = 48/x^2

Find y when x=5. Can you do this now?

by / did u mean division?

 

[notnek01]

by / did u mean division?

Yes. 1/x^2 means a fraction with numerator 1 and denominator x squared.

 

[fbyfbyfby]

Yes. 1/x^2 means a fraction with numerator 1 and denominator x squared.

thnx i solved it ans is 1.92 )