Mathematics: Post your doubts here!

[Faaiz Haque]

Binyamine solved it here :¬

Can't view that.
:l

 

[Snowysangel]

A question from s1:
A committee of 6 ppl, which must contain at least 4 men and at least 1 woman, is to be chosen from 10 men and 9 women.
A) find the no of possible committed that include either Albert(man) or tracey(woman) but not both.

 

[Thought blocker]

Can't view that.
:l

Dont you have access to youtube?

 

[Haya Ahmed]

Hey guys !! How to solve
Q31 and Q36 !! thanks

 

[loveyuan]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w13_qp_32.pdf

question number 4 anyone ？><

 

[Kushal lodha 5336]

Does anyone have question set topic wise for AS statistics?
I'm done wid the past papers...!!

 

[ZaqZainab]

Hey guys !! How to solve
Q31 and Q36 !! thanks

I couldnt understand 31 yet
but here is 36
I use the normal division method (Explained in the P3 text book)

We have 4x^4 +0ax^3 -9a^2x^2 +2(a^2-7)x -18
and 2x-3a


(EDITED) I just got 31
multiply (x-root of3) with (x+root of 3)
you will get the 1st quadratic factor
to find the next you have to carry out division just like i did in 36

 

[emma914]

can anyone solve question number 8 and 10 please?

 

[Wolfgangs]

Can someone please help me with this question? Explain?

Answers: i - 12
ii - 8.45m
iii - 13
iv - 5.41m

 

[Crimson-Saint]

how to do (ii)? w09qp11 and any type of questions like that

 

[CaptainDanger]

Can I get a step by step solution for both these parts? (Mentioning all the identities!)
For the 2nd one, just explain how do we get to the second step and how does under-root 2 become just 2 in the next step?
Thanks in advance!

 

[ZaqZainab]

Can someone please help me with this question? Explain?

Answers: i - 12
ii - 8.45m
iii - 13
iv - 5.41m

s=-1.25
u=?
v=?
a=10
t=2.5
(units omitted because I keep thinking the "s" in "m/s" is related to displacement)
(Positive direction is upwards, hence negative acceleration)

i) The initial speed upwards

s=ut+0.5at^2
-1.25=2.5u-31.25
2.5u=30
u=12

ii) The greatest height reached

Here, we find the position where the ball reached zero velocity due to gravity.

From the previous question, we can see that u=12, and in this case, v=0, and a=-10

v=u+at
0=12-10t
10t=12
t=1.2

Now, we find the distance travelled:

s=(u+v)t/2
s=12*1.2/2
s=7.2

Don't forget to add 1.25, as this was the starting point. So, the ball actually reaches 8.45m into the air.

iii) The speed of the ball upon first impact with the ground

We know at the top of the flight, velocity is zero, so set u=0.
We also know that a=10 (this time, positive velocity is downwards).

The total time is 2.5, and 1.2 of that is spent travelling upwards. This means that the ball fell 1.3 seconds.

v=u+at
v=10*1.3
v=13

iv) The greatest height after the first bounce

The ball bounces up at the speed of 12.8. We know at the top of its bounce, v=0, and we also know that a=-10

So:

v=u+at
0=12.8-10t
10t=12.8
t=1.28

And with s=t(u+v)/2:

s=1.28(12.8)/2
s=8.192

(not done by me)

 

[Faaiz Haque]

Can someone help me with this question please and explain.
Q9ii) http://papers.xtremepapers.com/CIE/...AS Level/Mathematics (9709)/9709_w06_qp_1.pdf

And
Q5)http://papers.xtremepapers.com/CIE/...AS Level/Mathematics (9709)/9709_w05_qp_1.pdf

 

[jungly krinsky]

please help with question 8 ii
http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s12_qp_11.pdf
http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s12_ms_11.pdf
Don't realy undertand what I am being asked to do here.

 

[SitiPutri]

please help with question 8 ii
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_qp_11.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_ms_11.pdf
Don't realy undertand what I am being asked to do here.

To find the range you have to know the minimum and maximum value of f(x). See, (x-2)^2 for any x CAN'T be negative because it's a square. And since it can't be negative, so its least value must be 0, right?

From there we can get f(x) = -4 + k for the minimum value of f(x). And for the maximum value, it's just simply infinity because there's no other limitation.

Thus, the range is f(x) > -4 + k

 

[jungly krinsky]

Thank you for explaining. I think I've got it now.

 

[Faaiz Haque]

Question 8 pls

http://papers.xtremepapers.com/CIE/...AS Level/Mathematics (9709)/9709_s07_qp_1.pdf

 

[SitiPutri]

Question 8 pls

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s07_qp_1.pdf

I didn't attempt to do the sketch, though.

 

[MarcoReus]

Which L.Bostock book covers Binomial Expansion?

Or should I refer to the O Level Add Maths book?

 

[asadalam]

Can someone help with complete Q11,and the 2 circled parts on the other page?
F.Z.M. 7
Awesome12
MarcoReus
M.Omar