Mathematics: Post your doubts here!

[aalmuhannadi]

Hi,

Can someone please explain how to work out:

Q11av (0580_s11_qp_43)
Q11bv

Q9bi (0581_s10_qp_43)

Thank you

 

[sud201196]

@aalmuhannadi
m/j 2011 0580 qp 43
Q11 a v) ans 2+4+6+..................+800 = 2(1+2+3+...................+400) because twice of 1 is 2, twice of 2 is 4 and so on till 400. therefore 2+4+6+............+800 = 2(1+2+3+....................+400)

Q11 b v) ans FIRST of all take out the square root of 278 784 (because sum of first n numbers = square root of the sum of first n cube numbers. so square root of 278 784 is 528 and the sum of first 32 numbers = 528 . therefore the answer for this question is 32.

may june 2010 qp 43

Q9 b i) ans 2/y + 4/(y-4) = 2/3 hours

(2y-8 + 4y)/y^2 - 4y = 2/3

3(6y-8) = 2y^2 -8y

18y-24 = 2y^2 - 8y

2y^2 - 8y -18y + 24 = 0

2y^2 - 26y + 24 = 0 ( divide equation by 2 )

y^2 - 13y + 12 = 0

 

[excited]

http://www.xtremepapers.com/CIE/Cambrid ... _qp_41.pdf -------------> Question 9 (e) HelP!!

 

[XPFMember]

http://www.xtremepapers.com/CIE/Cambridge%20IGCSE/0580%20-%20Mathematics/0580_s11_qp_41.pdf -------------> Question 9 (e) HelP!!

Assalamoalaikum!!

This is to be done by trial and error method...
Mark different combinations when x + y = 9

Calculate the costs...and check which one's the smallest!

 

[Achmerd]

I have a doubt...pls need HELP!!! this is the question... i donno how to do these questions. its very difficult for me to understand.. so can any one explain this to me (with workings) pls pls...

1 (a) The scale of a map is 1:20 000 000.
On the map, the distance between Cairo and Addis Ababa is 12 cm.

(i) Calculate the distance, in kilometres, between Cairo and Addis Ababa.

Answer (a)(i) ________________km[2]

(ii) On the map the area of a desert region is 13 square centimetres.
Calculate the actual area of this desert region, in square kilometres.
Answer (a)(ii)________________ km2 [2]

(b) (i) The actual distance between Cairo and Khartoum is 1580 km.
On a different map this distance is represented by 31.6 cm.
Calculate, in the form 1 : n, the scale of this map.
Answer (b)(i) 1 : ____ [2]

(ii) A plane flies the 1580 km from Cairo to Khartoum.
It departs from Cairo at 11 55 and arrives in Khartoum at 14 03.
Calculate the average speed of the plane, in kilometres per hour.
Answer (b)(ii) ________________km/h [4]


Total [10m]

 

[Martee100]

Could someone help me n this question>

Heres the question http://www.xtremepapers.com/CIE/Cambridge IGCSE/0580 - Mathematics/0580_s03_qp_4.pdf

Q6 the mensuration one! Thanks

 

[excited]

a) Volume of cuboid = l x b x h ------> 2x (x + 4)(x + 1)

2x^2 + 8x +(x + 1)

2x^3 + 10^ 2 + 8x cm


b) REMEMBER 1cm thick <----------

Therefore , assume 2x as length 1cm thick lower and 1cm thick at the top
So, (2x - 2)

Now assume (x + 4) as width 1cm thick lower and 1 cm thick at the top
So, (x+4) - 2 ----------> (x+2)

Now the one which is left is height -----> REMEMBER BE CAREFUL IN THIS STEP
because , here thickness is the taller part
(x + 1) - 1 -----------> Therefore the answer is (x)


THREE DIMENSION ARE :- (2x - 2) , (x + 2 ) , (x)


Volume of cuboid = l x b x h ------------> (2x - 2) x (x + 2) x (x)
= 2x^3 + 2x^2 – 4x


NOW :- Use simultaneous equation for subtraction between the external volume and internal volume to get the volume of wood

c) FOR THIS QUESTION i) use quadratic equation

2x^2 + 3x - 495 = 0 ---->

Iam unable to complete the quadratic equation because certain symbols are unavailable in XPF



IF I HELPED YOU PRESS THE THANK BUTTON!!! :Yahoo!: :Yahoo!: :Yahoo!: :Yahoo!: :Yahoo!: :Yahoo!:

 

[Achmerd]

@ XPF member.
Can u pls helpme out to do this question
http://www.xtremepapers.com/CIE/Cambrid ... 9_qp_4.pdf
Qeustion 6(b) (c) (d) (e) & (f)
any help appreciated! thanks in advance!!!

 

[Achmerd]

Re: IGCSE Maths Help--Available Here--Any Question

Another TIP:dont think that the question is hard if u cant get the ans. look in the question and ans. to the previous parts for eg see the probability question in june 2009 the question wil make u find the ans. in they earlier parts which r usually needed later in the question

Thanks XPF member!! v useful tips
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Can u pls helpme out to do this question
http://www.xtremepapers.com/CIE/Cambrid ... 9_qp_4.pdf
Qeustion 6(b) (c) (d) (e) & (f)
any help appreciated! thanks in advance!!!

 

[hamza96]

n
hii......confused in this thngy dunnoe how to solve it..... question goes like his..... 32 =1 .....how to find n in these kind of questions......need help fast .....got ma exam on 27th....thnxx

 

[Achmerd]

@ XPF Member,
Could u pls help me 2 solve this question.
http://www.xtremepapers.com/CIE/Cambrid ... _qp_22.pdf
Question no: 6 and 18!!!

 

[Achmerd]

@ XPF Member,
Could u pls help me 2 solve this question.
http://www.xtremepapers.com/CIE/Cambrid ... _qp_22.pdf
Question no: 6 and 18!!!

HELP!!! :Bravo:

 

[excited]

Q.6) First find the determinant by multiplying the |A| ----> -12 x 0 - - 4 x 1 = 0- - 4 = 4
|B|------> -4 x 3 - 4 x 0 = -12 - 0 = -12


Now to ---> Calculate the value of 5 |A| + |B|


5(4) + -12 = 20 - 12 = 8


EASY!!! :friends:

 

[excited]

OPEN THE ATTACHMENT FIRST TO KNOW THE POINTS


Value of m = 2 , Because both the lines are parellel, therefore the gradient is the same!

As y=2x + 8 crosses both the y-axis and x-axis. we use X=0 For Y- Axis
Y=0 For X-Axis

So, Apply this rule for finding y= 2x + 8


y = 2 (0) + 8 0 = 2x + 8
= 0+ 8 = 8 2x = 8 - 0
x = 4

0 = 2x + c
2x = c -0
5 = c -o /2
-10c = -0
c = 10

FINAL ANSWERS :- m=2 and c = 10

:good: :good: :good: :good: :good: :good: :good: :good: :good: :good: :good: :good:

 

[XPFMember]

@ XPF member.
Can u pls helpme out to do this question
http://www.xtremepapers.com/CIE/Cambrid ... 9_qp_4.pdf
Qeustion 6(b) (c) (d) (e) & (f)
any help appreciated! thanks in advance!!!

Assalamoalaikum!!

These are simple..

(b) (i) Draw a line y=20 and write the solutions...

remember there are two ways of finding the intersecting points(solutions)
either from graph
or by solving simultaneously

in this case you've to do by drawing appropriate lines and write the x/y coordinates, as appropriate, of the intersecting points

(c) Use the formula (y2 - y1)/(x2-x1)

(d) It'll be a parallel line to g(x) being 10 small blocks below it...as it says y=g(x) - 10

(e) When you dray a tangent, the line will be horizontal so eqn will be y= -27

(f) Draw lines x = –3, x = –2, y = 40 (y=g(x) already there)

By shading the unwanted regions, find the region R!

 

[xXRUSHXx]

I have a question haha:

A spherical balloon of radius 3 metres has a volume of 36π cubic metres.
It is further inflated until its radius is 12 m.
Calculate its new volume, leaving your answer in terms of π.

The answer is 2304π but I have no clue how they got the answer. ardon:

Thanks in advance.

 

[Achmerd]

0 = 2x + c
2x = c -0
5 = c -o /2
-10c = -0
c = 10

Why is c=10 it should be -10.because......
y=mx+c
0=2x5+c
0=10+c
10+c=0
c= -10
is it????? :unknown: so why is c=10 in your answer.... need more explaination. pls pls pls

 

[XPFMember]

Assalamoalaikum!!

Yes c = -10! he made a mistake!

 

[Achmerd]

Assalamoalaikum!!

Yes c = -10! he made a mistake!

thanks v much .... all doubts cleared!!!! 8)

 

[excited]

iam soooo sorry typing mistake!! Srry !! But plzz thank me for the steps!