Mathematics: Post your doubts here!

[Soldier313]

Reposting:

Aoa wr wb

Can someone please tell me, how do we know when we have to use what value
eg for this qn, how do we know it's 5 rather than 4.5 rather than 4.5 etc

View attachment 26423

Thank you.

xhizors Ashique or anyone taking statistics?

 

[AlishaK]

AlishaK

6) (i) 14P12 = 4.36 x10^10 [P.S, use calculator]
See, there are 14 places, and thus we permutate 12. (This is more like a rule)

(ii) Here I got stuck, but Alhamdulilah, I found littlecloud11 post, below.

(iii)I got stuck again, but Alhamdulilah found this post below

Now, the only this left is, 9 people are left, (12- (Mrs Lin + a student + Mrs Brown))
And 11 seats left (14 - 3)
so x 11P9
and divided by total number of permutation the answer we got at (i)

Later, will continue In Sha Allah.

Jazak Allah Khair!! Thanks a ton ! May Allah bless u! :')
U've no idea how grateful I'm to u. :')

Zenia ZZ THERE U GO!

 

[kiara15]

aoa,plz tel me why we subtract basic angle from pi in complex num? and how to draw loci in argand diagram?

 

[AlishaK]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s12_qp_32.pdf
Q4 ?! the identity. just show me a couple of steps..i'lll do the rest.
Thanks a lot

 

[Esme]

aoa,plz tel me why we subtract basic angle from pi in complex num? and how to draw loci in argand diagram?

Loci in Argand diagrams

 

[Esme]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_qp_32.pdf
Q4 ?! the identity. just show me a couple of steps..i'lll do the rest.
Thanks a lot

1/sin2x = 1/cosx + cosx/sinx
1/2sinxcosx = (sinx+cos^2x)/cosxsinx
1/2 = sinx + (1-sin^2x)
1/2 = sinx - sin^2x +1

Now I'm sure you can solve the quadratic equation

 

[Esme]

Can anyone solve this identity for me? cos4x-4cos2x+3=8sin^4x

cos4x - 4cos2x + 3
cos(2x+2x) - 4( 1- 2sin^2x) + 3
cos2xcos2x-sin2xsin2x -4 + 8sin^2x +3
(1-2sin^2x)^2 - (2sinxcosx)^2 + 8sin^2x -1
1-4sin^2x+4sin^4x - 4sin^2x(1-sin^2x) + 8sin^2x -1
4sin^2x + 4sin^4x - 4sin^2x + 4sin^4x
8sin^4x

I may have skipped a few steps but remember you have to replace all the cos with sin, wherever you can.

 

[AlishaK]

1/sin2x = 1/cosx + cosx/sinx
1/2sinxcosx = (sinx+cos^2x)/cosxsinx
1/2 = sinx + (1-sin^2x)
1/2 = sinx - sin^2x +1

Now I'm sure you can solve the quadratic equation

Argh! we had to use both the sides?! I was only using/solving LHS to prove RHS?!
Thanks a lot Esme!!
Jazak Allah khair!

 

[AlishaK]

Argh! we had to use both the sides?! I was only using/solving LHS to prove RHS?!
Thanks a lot Esme!!
Jazak Allah khair!

just realised the question says 'Solve' not 'Prove'...Thanku anyhow.

 

[Esme]

Argh! we had to use both the sides?! I was only using/solving LHS to prove RHS?!
Thanks a lot Esme!!
Jazak Allah khair!

Yeah I thought that might be your mistake
Anytime sis

 

[SararaIH]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w09_qp_31.pdf

Can someone please give me the solution to the whole of Q 6) , Q7 iv) and Q 10i

 

[AlishaK]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s12_qp_32.pdf
Q7 iii) I know how to do it. But what exactly do I have to show for '3 marks' ?!
Esme
Thank u! :')

 

[TaffsAsLevel]

Will we get full marks if we got our final answer correct but very short working? It is 6 marks but I got correct? Or you have to do the long way? Like if Find length AB given the line r=something and meets at plane p at A and plane q at B. Find AB length (June 2010 paper 32)

 

[Zsiddiqui]

Reposting:



xhizors Ashique or anyone taking statistics?

Sum of (fx) / sum of (f) = 27.5
(10+15f+330+240)/ 17+f
580+15f = (17+f)*(27.5)
580+15f = 467.5 + 27.5f
112.5 = 12.5f
f = 9

Total number of children = 2+9+11+4 = 26

 

[Arjun Dhanak]

Hi. I need to know when we use vector cross product and what the reason for using it is. What is the outcome of doing vector product?
Thanks in advance.
-Arjun

 

[Soldier313]

Sum of (fx) / sum of (f) = 27.5
(10+15f+330+240)/ 17+f
580+15f = (17+f)*(27.5)
580+15f = 467.5 + 27.5f
112.5 = 12.5f
f = 9

Total number of children = 2+9+11+4 = 26

Thanx sis for that, the pro is i know the method, however, i was using 4.5 rather than 5, 14.5 rather than 15 etc
so my qn is how do i know when i am supposed to use what, coz there are some circumstances when we'd have to use the 4.5 rather than 5 etc.

 

[Arjun Dhanak]

Hi. I need to know when we use vector cross product and what the reason for using it is. What is the outcome of doing vector product?
Thanks in advance.
-Arjun

 

[SararaIH]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w09_qp_31.pdf

Can someone please give me the solution to the whole of Q 6) , Q7 iv) and Q 10i

 

[syed1995]

Reposting:



xhizors Ashique or anyone taking statistics?

Link?

I would suggest that you use... https://www.xtremepapers.com/commun...tics-doubt-post-your-doubts-here.25911/page-6 to ask for S1 questions .. as most of the people are not posting their S1 questions/watching this thread.. because of the P3 on Monday..

 

[Soldier313]

Link?

I would suggest that you use... https://www.xtremepapers.com/commun...tics-doubt-post-your-doubts-here.25911/page-6 to ask for S1 questions .. as most of the people are not posting their S1 questions/watching this thread.. because of the P3 on Monday..

oh right, thank you.