Mathematics: Post your doubts here!

Dug

Dug

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hm12 said:
http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_w11_qp_12.pdf
http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_w11_ms_12.pdf
please explain question 3 part (ii)
Click to expand...
AB = OB - OA
AB = -3i +6j +2k
Lets name the req vector PQ,
PQ = x(-3i + 6j +2k) ------------1

|PQ| = √(-3x)^2 + (6x)^2 + (2)^2
Acc to the question,
√9x^2 + 36x^2 + 4x^2 = 28
9x^2 +36x^2 + 4x^2 = 784
49x^2 = 784
x^2 = 784/49
x^2 = 16
x = ±4
Since the directions are same, x cannot be negative.
Put this value in equation 1 and you will get PQ = -12i + 24j +8k
 
Dug

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iKhaled said:
need help...M/J 09

Q10, part ii and iv? :S hate functions from my heart!! :mad:

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s09_qp_1.pdf
Click to expand...
From part i, you have f(x)=2(x-3)^2 - 5
ii) The coordinates of the vertex are (3,-5) from which we can deduce that x=3 is the line of symmetry. We actually divided the curve into two parts with this line. To get the other half back, we multiply it by 2. A bit difficult to explain but I hope you got it. :rolleyes:
iv) What happens when you split a curve at the turning point? It becomes a one-to-one function.
 
H

hm12

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Dug said:
AB = OB - OA
AB = -3i +6j +2k
Lets name the req vector PQ,
PQ = x(-3i + 6j +2k) ------------1

|PQ| = √(-3x)^2 + (6x)^2 + (2)^2
Acc to the question,
√9x^2 + 36x^2 + 4x^2 = 28
9x^2 +36x^2 + 4x^2 = 784
49x^2 = 784
x^2 = 784/49
x^2 = 16
x = ±4
Since the directions are same, x cannot be negative.
Put this value in equation 1 and you will get PQ = -12i + 24j +8k
Click to expand...
thanks a lot for your help:)
 
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iKhaled

iKhaled

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Dug said:
From part i, you have f(x)=2(x-3)^2 - 5
ii) The coordinates of the vertex are (3,-5) from which we can deduce that x=3 is the line of symmetry. We actually divided the curve into two parts with this line. To get the other half back, we multiply it by 2. A bit difficult to explain but I hope you got it. :rolleyes:
iv) What happens when you split a curve at the turning point? It becomes a one-to-one function.
Click to expand...
Oo is there a link to that explanation :S:S ?
 
leadingguy

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M1 done but wont reply to those qstns:eek:
as itx a long time I did that:D

wheras s1 currently giving :)
so U can expect replY

wat Abt p1 and p3 ?? theY are Awsome;)
 
Dug

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Esme said:
i have no idea what converging and diverging rays are.. :eek:
Click to expand...


converging_35865_md.gif


i4.jpg


I hope that was not a joke. :ROFLMAO:
 
Esme

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Correct me if im wrong plz :
fx has a domain of x>a
gx has a domain of x>b
therefore the domain of gfx will be x>a.
 
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