Mathematics: Post your doubts here!

[littlecloud11]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w12_qp_31.pdf

question 9 ii) please!!

This is how I do it.
The two complex roots are 1+√2i and 1-√2i
If you kept it in the form of factors it would be [x-(1+√2i)] and [x-(1-√2i)]. These are the two factors of p(x)
If you multiply these two factors you get a quadratic equation.
(x-1-√2i) * (x-1+√2i)
= x^2 -x +√2xi -x +1 -√2i -√2ix +√2i -(√2i)^2
=x^2 -2x +1 +2
=x^2 -2x +3

Now use long division to divide p(x) by this quadratic factor to get the other two factors.
Hope this helps!

 

[Gordious]

Can someone help me with these?
http://papers.xtremepapers.com/CIE/...AS Level/Mathematics (9709)/9709_s06_qp_3.pdfQ2. I am getting two different answers by doing two different methods: 1) Squaring both sides 2) 2x> x-1 and -2x<x-1

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s11_qp_32.pdfQ6ii; what will be the shape of the curve?

http://papers.xtremepapers.com/CIE/...AS Level/Mathematics (9709)/9709_s03_qp_3.pdfQ8ii

 

[LMGD33]

After I went through the question. The initial mass (t=0) of substance B, which is also y is 70. The question asks for percentage mass remaining. Since the mass remaining as t increase to infinite is 70/e, the percentage mass remaining should be (remaining/initial) x 100 , which is also [(70/e)/70]x100.
I hope you understand it. =)

Is it something like this? Then i tend to infinity and obtain P = 100/e


THANK YOU SO MUCH!! Remembered in my prayers!

 

[PhyZac]

In both cases? whether its sqroot of a number or complex root?

When we have a complex root, to state the other complex root, we take its conjugate.

 

[Gordious]

1/(2x-1)(x-1) . Find the bionomial expression upto x^3 and find the range of values of x for this expression is valid.
For range, the ans is -0.5<x<0.5, how?

 

[VinnCh]

Is it something like this? Then i tend to infinity and obtain P = 100/e

View attachment 26639
THANK YOU SO MUCH!! Remembered in my prayers!

Yes, you are right! I am glad that you understood the question. =)

 

[abbey789]

Given that y = 0 when x = 1, solve the differential equation
xydy =y2 +4, dx
obtaining an expression for y2 in terms of x.
http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s10_qp_31.pdf
Question 5. PLEASE!

 

[Soldier313]

Aoa wr wb
Can someone please give me a detailed explanation for qn 10 ii of this paper, how do they get the vector parallel to the plane, but not parallel to line l
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s05_qp_3.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s05_ms_3.pdf


Thank you .

And qn 10 ii of this paper please

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w12_qp_31.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w12_ms_31.pdf

littlecloud11 PhyZac Esme and everyone else doing p3

 

[farhan143]

Can some one give me a detailed explanation for the follwing question
2012 - MJ - 9709 - Statistics - AS - p61-

 

[SonalDhanturi]

13 sin(2x + 67.38) = 11
Now solve it

I tried that, i got x= -9.6 (1dp). Thats apparently the wrong answer

 

[Silent Hunter]

How to do further than this : -ln 4 - ln 2 .... wil it be ln (4/2) ..... the blue minus is confusing me ?

any one?

Rutzaba
Esme

anyone ? thanks alot

 

[iKhaled]

How to do further than this : -ln 4 - ln 2 .... wil it be ln (4/2) ..... the blue minus is confusing me ?

any one?

Rutzaba
Esme

anyone ? thanks alot

-ln4-ln2 = -(ln4+ln2) = -ln(4x2) = -ln8

 

[Esme]

How to do further than this : -ln 4 - ln 2 .... wil it be ln (4/2) ..... the blue minus is confusing me ?

any one?

Rutzaba
Esme

anyone ? thanks alot

It'll be ln( 1/(4x2) )

 

[Silent Hunter]

It'll be ln( 1/(4x2) )

with a positive sign ?

 

[TaffsAsLevel]

It's better you show all the steps for whichever method you choose. Because with vectors there's always more than one way to obtain answer. You can do whatever way seems easy or short to you but show how you've done it.

it's actually june 2010 paper 32 qp 9. (ii) 6 marks where they ask find the length of AB, given the line equation that meet the plane p at A and plane q at B so that AB direction vector would just be the direction vector given in the line eq. so instead I just find |AB| magnitude and got the correct answer, that's very short and I got 3 which is correct in markscheme. So should I explain it in words then?

 

[Esme]

with a positive sign ?

Yep. The answer on your calculator will automatically be negative. It's like writing :
ln1 - ln4 - ln2 which is the same as 0-ln4-ln2= -ln4-ln2

 

[Esme]

And qn 10 ii of this paper please

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w12_qp_31.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w12_ms_31.pdf

littlecloud11 PhyZac Esme and everyone else doing p3

Okay hold on...lemme have a look at the question.. Vectors is my least favourite topic, so I usually skip explaining those questions.

 

[Soldier313]

Aoa wr wb'
Could someone please urgently post some good short notes on vectors??
JazakAllah khair!

 

[Esme]

it's actually june 2010 paper 32 qp 9. (ii) 6 marks where they ask find the length of AB, given the line equation that meet the plane p at A and plane q at B so that AB direction vector would just be the direction vector given in the line eq. so instead I just find |AB| magnitude and got the correct answer, that's very short and I got 3 which is correct in markscheme. So should I explain it in words then?

I don't think you should have to... but I can't be certain

 

[Soldier313]

Okay hold on...lemme have a look at the question.. Vectors is my least favourite topic, so I usually skip explaining those questions.

Thanx a ton sis!