Mathematics: Post your doubts here!

[A.Q]

can some1 tell me the solution of the following question (its in Oct/Nov 2010, 9709/32, Q7 Part(ii))

With respect to the origin O, the points A and B have position vectors given by
−−→
OA = i + 2j + 2k and
−−→
OB = 3i + 4j. The point P lies on the line AB and OP is perpendicular to AB.

(ii) Find the position vector of P.

 

[Khan_971]

how did u get it.... plz xplain

Take (tan^2 x +1) common, in the 1st question. sec^2 x substitute.
Perform substitution in the same 2 questions until u get the eq in the 2nd last step of 10(i) then just put the corresponding N value

 

[redapple20]

this is stats. plx help how to do.
A factory makes a large number of ropes with lengths either 3 m or 5 m. There are four times as many
ropes of length 3 m as there are ropes of length 5 m.
) One rope is chosen at random. Find the expectation and variance of its length

 

[redapple20]

prove the identity sin^2 (2x) (cosec^2 (x)-sec^2 (x))= 4cos2x

 

[A.Q]

can some1 tell me the solution of the following question (its in Oct/Nov 2010, 9709/32, Q7 Part(ii))

With respect to the origin O, the points A and B have position vectors given by
−−→
OA = i + 2j + 2k and
−−→
OB = 3i + 4j. The point P lies on the line AB and OP is perpendicular to AB.

(ii) Find the position vector of P.

 

[redapple20]

ob

can some1 tell me the solution of the following question (its in Oct/Nov 2010, 9709/32, Q7 Part(ii))

With respect to the origin O, the points A and B have position vectors given by
−−→
OA = i + 2j + 2k and
−−→
OB = 3i + 4j. The point P lies on the line AB and OP is perpendicular to AB.

(ii) Find the position vector of P.

OB-OA will give b1 form equation of line ab. which will b 3i + 4j +t(2i +2j -2K) any point on this line would b x= 3+2t y=4+2t z=-2t let this b p. then line op will have b2 OP-OO . this dot producted with b1 will be equals to 0. u will get a certain value of t substitute into (x y and z)

 

[redapple20]

ob


OB-OA will give b1 form equation of line ab. which will b 3i + 4j +t(2i +2j -2K) any point on this line would b x= 3+2t y=4+2t z=-2t let this b p. then line op will have b2 OP-OO . this dot producted with b1 will be equals to 0. u will get a certain value of t substitute into (x y and z)

t is -7/6 answer is(2/3i +5/3j +7/3k) ..... i think lol

 

[1357913579]

can some one check and tell me whether the questions i have solved as coorect or not?

 

[XPFMember]

http://www.xtremepapers.com/CIE/Interna ... _qp_31.pdf
q10. part (i) help me out

aoa wr wb

i need help with this question too..

 

[Esme]

A factory makes a large number of ropes with lengths either 3 m or 5 m. There are four times as many
ropes of length 3 m as there are ropes of length 5 m.
) One rope is chosen at random. Find the expectation and variance of its length[/quote]

ummm.....is this AS stats ??

 

[Esme]

can anyone please explain S1 ctober/ novemeber 2009 (variant 1) question 5 part a (ii)

Even i have problems with permutations and combinations but there arent many here who help out in stats. mostly jus pure maths.

 

[1357913579]

aoa wr wb

i need help with this question too..

here you go
soory for the messy handwriting and iam not sure about the order

 

[XPFMember]

Even i have problems with permutations and combinations but there arent many here who help out in stats. mostly jus pure maths.

Permutations and Combinations (my explanation)- P6

 

[XPFMember]

here you go
soory for the messy handwriting and iam not sure about the order

Assalamoalaikum wr wb!
well jazakAllahu khairen...
I just cudnt get the first step...i didnt try the rest...my mistake was not taking 3600 to the other side..!
i'll try doing this again now...
and btw it isnt messy
thanks a lot! jazakAllahu khairen

 

[1357913579]

Assalamoalaikum wr wb!
well jazakAllahu khairen...
I just cudnt get the first step...i didnt try the rest...my mistake was not taking 3600 to the other side..!
i'll try doing this again now...
and btw it isnt messy
thanks a lot! jazakAllahu khairen

Walikmassalam
your welcome

 

[1357913579]

can somone please explain how to solve pure 3 :november 2007 :question 7 (ii) and (iii)

Assalamoalikum,
here you go
soory iam not sure about the order

 

[Mr Me]

Can anyone help me out with Q. no 3:
Question: Oct/Nov 2011 Paper 41
Marking scheme: Oct/Nov 2011 Paper 41

 

[1357913579]

can someone please explain how to solve this question

can some please solve this.

 

[Uneeq]

Thanks for your effort. I'm sorry but I couldn't get the last part. How did you get 5<4 and -4<+1 ... what did you refer to ?

 

[Esme]

Permutations and Combinations (my explanation)- P6

ummmmm......yea thank you but this is jus the basics. The questions in the tutorial are easy to solve n understand. However, i go totally blank wen i see questions like this :

If possible plz explain the iii) iv) n v) bit .

Here's the mark scheme: http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_w10_ms_61.pdf