Author Topic: Add. Maths!!!!! please help slvri/Astar math  (Read 3536 times)

Offline ~~~~shreyapril~~~~

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Add. Maths!!!!! please help slvri/Astar math
« on: October 20, 2009, 03:11:59 pm »
i have this question please answer it Astar math or slvri i need help
Please help wid diagram if possible..


Points A and B have position vectors a and b respectively relative to the origin O. The point C lies on OA produced such that OC = 2OA, and d lies on OB such that OD = 1/3OB

i) Express BC and DA in terms of a and b
   The lines AD and BC intersect at P when extended
ii) Given that AP = mDA, express OP in terms of m, a, b
iii) Given also that BP = kBC, express OP in terms of k, a, b
iv) Hence calculate the value of m and k and the position vector of p
v) Another point Q is such that APCQ is a parallelogram. Find its position vector.

« Last Edit: October 20, 2009, 03:34:18 pm by ~~~~shreycool~~~~ »
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Offline astarmathsandphysics

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Re: Add. Maths!!!!! please help slvri/Astar math
« Reply #1 on: October 20, 2009, 03:36:32 pm »
here

Offline ~~~~shreyapril~~~~

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Re: Add. Maths!!!!! please help slvri/Astar math
« Reply #2 on: October 20, 2009, 03:47:22 pm »
tks sir
i did not get the step in the attachment
how come QC = AP
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Offline ~~~~shreyapril~~~~

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Re: Add. Maths!!!!! please help slvri/Astar math
« Reply #3 on: October 20, 2009, 03:48:38 pm »
i guess 2a - (3a - b) = b-a
rite?? or not??
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Offline astarmathsandphysics

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Re: Add. Maths!!!!! please help slvri/Astar math
« Reply #4 on: October 20, 2009, 03:49:03 pm »
Because QCAP is a paralellogram. It goes APQC so AP is antiparalle to QC so paralell to CQ. I should have crawn it on. Sorry.

Offline astarmathsandphysics

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Re: Add. Maths!!!!! please help slvri/Astar math
« Reply #5 on: October 20, 2009, 03:49:47 pm »
i guess 2a - (3a - b) = b-a
rite?? or not??

yes my mistake

Offline ~~~~shreyapril~~~~

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Re: Add. Maths!!!!! please help slvri/Astar math
« Reply #6 on: October 20, 2009, 03:50:51 pm »
k thanx sir got it...
i will come back if i have some more doubts

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Offline Ghost Of Highbury

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Re: Add. Maths!!!!! please help slvri/Astar math
« Reply #7 on: October 20, 2009, 04:20:46 pm »
refer to the diagram..

1) BC = 2a - b
    DA = -b/3 + a
2) OP = OA + AP
    OP = a(1+m) -mb/3
3)   OP = OB + BP
      OP = b + 2ak - bk
4)    2k = 1 + m
       1 - k = -m/3
solve them
m =3
k=2
---------
first find QC = AP = 3a - b

therefore, CQ = b-3a

OQ = OC + CQ

= 2a + b - 3a = b-a
-----
« Last Edit: October 20, 2009, 04:28:24 pm by ~AM~ ?!?! »
divine intervention!

Offline ~~~~shreyapril~~~~

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Re: Add. Maths!!!!! please help slvri/Astar math
« Reply #8 on: October 21, 2009, 11:33:10 am »
go it mannn
thanx.
by the way what name did you give to the image??
dhan tana!!!
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Offline astarmathsandphysics

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Re: Add. Maths!!!!! please help slvri/Astar math
« Reply #9 on: October 21, 2009, 12:08:28 pm »
AM I will have to learn to do images as good as that.

Offline Ghost Of Highbury

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Re: Add. Maths!!!!! please help slvri/Astar math
« Reply #10 on: October 21, 2009, 12:09:27 pm »
AM I will have to learn to do images as good as that.

sir, its nuthing complicated..use MS paint..
thats it!
divine intervention!

Offline ~~~~shreyapril~~~~

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Re: Add. Maths!!!!! please help slvri/Astar math
« Reply #11 on: October 23, 2009, 11:43:28 am »
i thought you used photoshop cause i heard u pretty well in it
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Offline astarmathsandphysics

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Re: Add. Maths!!!!! please help slvri/Astar math
« Reply #12 on: October 23, 2009, 12:21:58 pm »
At themoment i only use openoffice. I dont have much ms software.

Offline ~~~~shreyapril~~~~

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Re: Add. Maths!!!!! please help slvri/Astar math
« Reply #13 on: October 23, 2009, 05:26:49 pm »
ohh
y dont u use a torrent and download it
By the way i guess paint is by default in every pc i guess
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Offline astarmathsandphysics

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Re: Add. Maths!!!!! please help slvri/Astar math
« Reply #14 on: October 23, 2009, 05:32:59 pm »
I will get ms office