Author Topic: CIE Pure Mathematics Paper 1 Doubt  (Read 1283 times)

Offline Dania

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CIE Pure Mathematics Paper 1 Doubt
« on: September 21, 2010, 08:53:25 pm »
I need HELP, please!

How do I show that the mid-points of 2 3D vectors coincide?

Also,

(a) The fifth term of an arithmetic progression is three times the second term, and the third term is 10.
Find (i) the first term, (ii) the common difference, (iii) the 20th term.

(b) The nth term, t(n), of a sequence is given by - t(n) = p + nq, where p and q are constants.

(i) Write down, in terms of p and q, the 6th term of the sequence.
(ii) Find, in terms of p and q, the sum of the first six terms.



:)

Offline S.M.A.T

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Re: CIE Pure Mathematics Paper 1 Doubt
« Reply #1 on: September 22, 2010, 10:39:03 am »
a)i)
2nd term=a+d
 5th term=a+4d

a+4d=3×(a+d)
d=2a

a+2d=10
a+(2×(2a))=10
5a=10
a=2

ii)d=2×2=4
iii)20th term=2+(19×4)=78

b)i)t(6)=p+6q
    
   ii)sum=(n/2)×(L+a),where L is last term
           =(6/2)×(p+6q+p+q)
           =3×(2p+7q)
           =6p+21q
  
« Last Edit: September 22, 2010, 10:44:45 am by asiftasfiq93 »


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Offline Dania

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Re: CIE Pure Mathematics Paper 1 Doubt
« Reply #2 on: September 22, 2010, 12:06:59 pm »
Thank You :)
:)

Offline Dania

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Re: CIE Pure Mathematics Paper 1 Doubt
« Reply #3 on: September 22, 2010, 05:50:41 pm »
By the way, would you happen to know how I would show that that 2 vectors coincide?
:)

Offline S.M.A.T

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Re: CIE Pure Mathematics Paper 1 Doubt
« Reply #4 on: September 23, 2010, 02:48:49 am »
By the way, would you happen to know how I would show that that 2 vectors coincide?
here
See post number 378&379 :)

If you have problem please tell me :)
« Last Edit: September 23, 2010, 02:50:32 am by asiftasfiq93 »


"A man's life is interesting primarily when he has failed - I well know. For it's a sign that he tried to surpass himself." Clemenceau, Georges

Offline astarmathsandphysics

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Re: CIE Pure Mathematics Paper 1 Doubt
« Reply #5 on: September 24, 2010, 02:27:50 pm »
I did a page on my website. Will post a link when I get home.

Offline astarmathsandphysics

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