Mathematics: Post your doubts here!

[InnocentAngel]

Please help me with this simple question in s1 :
how does a sample differ from a population?

 

[applepie1996]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s06_qp_3.pdf
could someone please solve question 9 (ii)
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s07_qp_3.pdf
question 2 (ii)
question 7 (ii)

 

[syed1995]

how r u long time no see?

I am pretty good mate how are ya..?

 

[A star]

I am pretty good mate how are ya..?

not counting studies fit

 

[Rutzaba]

i think i have been ignoring this thread badly... lets divide the ques to be done so that two of us are not solving the same question and end up ignoring another...

 

[syed1995]

not counting studies fit

haha pretty much the same here.. How's maths for ya.. ? should be pretty easy after last year.. right?

 

[Ashique]

Can someone please help me with question 6 part i?
http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s10_qp_61.pdf

 

[peter brown]

this is w12 paper 61. i did the first part. dont understand the second one. please help. i need help . i am frustrated. thanks.

Lengths of rolls of parcel tape have a normal distribution with mean 75 m, and 15% of the rolls have
lengths less than 73 m.
(i) Find the standard deviation of the lengths. [3]
Alison buys 8 rolls of parcel tape.
(ii) Find the probability that fewer than 3 of these rolls have lengths more than 77 m

 

[Manobilly]

Thanks I got the answer

Question number???

 

[MONJUR HASAN NISHAD]

Can someone explain Oct/Nov 2010 Paper 33 question 10 ii b? How the hell can you find the SIX roots? Please help me out!

 

[Khav19]

I really need some help
i am sure its simple but i completely forgot about it

1.Simply
mC3
Answer is m(m-1)/2
Can you show me the working step by step , i am having huge trouble in simplying these where either n or r is unknown

 

[Iffat]

Iffat
i hope this answers ur question for number 10 on the other ppr. where c is the x co-ordinate of the vertex.

thanx soo much

 

[Iffat]

ppl i need ur help
2007 may-jun p1:
q3 and q8(i)

2007 oct-nov p1:
q4(ii),(iii)

2008 oct-nov p1:
q2

 

[Tkp]

ppl i need ur help
2007 may-jun p1:
q3 and q8(i)
for number 3

(1-sin2x/cos2x)/ (1+sin2x/cos2x)
(cos2x - sin2x/ cos2x)/ (cos2x+ sin2x/ cos2x)
(cos2x - sin2x/ cos2x)/(1/ cos2x) cos2x cancels out and we get
cos2x- sin2x then 1- sin2x- sin2x=1-2 sin2x
8(i)
Put the values as told in the question
U will get 1st 1 a+b=-1
2nd one u will get a-b =7
Substitute and u will get the answer

 

[Tkp]

ppl i need ur help

fr the oct nov 07
equal the terms of 1st,4th,and 15 of arithmetic progression to 1,2,3 terms of geometric progression
a+4d=ar
a+14d=ar^2

substitute it and u will get the answer and the 3rd is easy

 

[Islam Atef]

I have a question

if in pure we were asked to sketch a graph we must draw it using graph paper and by scale????????????
or draw it with our hands and with no scale

 

[Iffat]

fr the oct nov 07
equal the terms of 1st,4th,and 15 of arithmetic progression to 1,2,3 terms of geometric progression
a+4d=ar
a+14d=ar^2

substitute it and u will get the answer and the 3rd is easy

cud u plz do it as i wasnt getting the ans

 

[Iffat]

huh? ..i didnt get q3 and for q8(i) how do ukno dat a+b=-1, y not a+b=7?

 

[salvatore]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w10_qp_13.pdf
Please help me solve qn no. 8 (ii).. I'm totally confused!
Thanks

 

[Kumkum]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w10_qp_13.pdf
Please help me solve qn no. 8 (ii).. I'm totally confused!
Thanks

okay, i'll try to explain.
First you have to find the length of the blue line. you have to use ' cos' to find it, lets call this line AX
so,
AX= 5c0s0.6 = 4.12 cm
now you will have to find the small length PX. to find PX u need to know the length of AQ, the length of AQ is 5cm because 'BQD' is an arc of a circle with center 'A' so it means its 5cm (the length AQ is the radius of the circle with center A)
so since u know AQ = 5cm, to find PX :
PX = 5 - 4.12 = 0.873 cm
but they are asking us for the length of PQ, so the length is 2*PX
===> PQ = 2*0.837
= 1.75 cm
hope u understood