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Mathematics: Post your doubts here!

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Here's what i've done:

argu = arg( (1+2i)/(1-3i) )
argu = arg(1+2i) - arg(1-3i)
arg(-1/2 + i/2) = tan^-1(2) - tan^-1(-3)
tan^-1(-1) = tan^-1(2) + tan^(3)
3π/4 = tan^-1(2) + tan^-1(3)

Hope you got it :)
yup i did that, in a pretty messy way thou. lol ... Thanku thanku! :)
 
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Wa laikum as salaam :)

S denotes integration

S (9-h)^-1/3
Now to integrate this you multiply by 3/2 and divide by -1. This gives -3/2
If you're wondering why we divide by -1, it's the coefficient of h. And when we integrate we divide by the coefficient of the variable.
 
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Wa laikum as salaam :)

S denotes integration

S (9-h)^-1/3
Now to integrate this you multiply by 3/2 and divide by -1. This gives -3/2
If you're wondering why we divide by -1, it's the coefficient of h. And when we integrate we divide by the coefficient of the variable.
oh right! Thank you so much for that :)
 
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Wa laikum as salaam :)

S denotes integration

S (9-h)^-1/3
Now to integrate this you multiply by 3/2 and divide by -1. This gives -3/2
If you're wondering why we divide by -1, it's the coefficient of h. And when we integrate we divide by the coefficient of the variable.
why do we divide by 3/2 ? i hope i dont sound dumb?! :oops:
 
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why do we divide by 3/2 ? i hope i dont sound dumb?! :oops:

Lol no you don't
Actually what you're doing is dividing by (n+1). In this case n=-1/3
n+1=2/3
So when you divide by 2/3, it is the same as multiplying by 3/2
 
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Lol no you don't
Actually what you're doing is dividing by (n+1). In this case n=-1/3
n+1=2/3
So when you divide by 2/3, it is the same as multiplying by 3/2
OMG!!! i feel so dumbo! u know what i read (9-h)^-1 is divided by '3'...hahaha ! i know that thing thou...lol thanks anyway.... c
 
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Can someone please explain to me q10 (iii)... i've been stuck on it for a while now... please help guys :/
Also please explain q7(iii) and q8(i).. in q8(i) i keep getting -10 instead of just 10u.. Just explain that point where im making the mistake.. thanks alot :D
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_qp_32.pdf
Marking scheme: http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_ms_32.pdf

Q7iii)

Here's what i've done:

argu = arg( (1+2i)/(1-3i) )
argu = arg(1+2i) - arg(1-3i)
arg(-1/2 + i/2) = tan^-1(2) - tan^-1(-3)
tan^-1(-1) = tan^-1(2) + tan^(3)
3π/4 = tan^-1(2) + tan^-1(3)

Hope you got it :)
 
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Can someone please explain to me q10 (iii)... i've been stuck on it for a while now... please help guys :/
Also please explain q7(iii) and q8(i).. in q8(i) i keep getting -10 instead of just 10u.. Just explain that point where im making the mistake.. thanks alot :D
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_qp_32.pdf
Marking scheme: http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_ms_32.pdf

As for Q8i) you're getting -10. that's correct. now you have to change signs because the limits have been exchanged. If you notice the limits are supposed to be (6-5)^1/2 and (6-2)^1/2
1 being your upper limit and 2 being the lower limit. However the question asks ask to write 2 as the upper limit and 1 as the lower limit. So when you exchange these limits you have to change the sign

Sounds a bit confusing but think about it, you'll get it
 
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http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w12_qp_33.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w12_ms_33.pdf

Q7iii) In such cases where they haven't given the initial value for the iteration formula, we just assume it to be 0 ?
MustafaMotani Told ya, I'd annoy you :p

Also, in complex numbers what is the square root of i ?

I dont know what sould be the initial value in such cases .. I think situation hints us what to take ...

square root of i = 1/root2 + i/root2
 
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I dont know what sould be the initial value in such cases .. I think situation hints us what to take ...

square root of i = 1/root2 + i/root2

Well in this case, there isn't any hint. And I did get the answer by taking 0, but I'm not sure if that's right.

Is there any method to arrive at 1/root2 + i/root2 ? Or it's just something we should know? I'm not exactly able to solve root of i
 
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Well in this case, there isn't any hint. And I did get the answer by taking 0, but I'm not sure if that's right.

Is there any method to arrive at 1/root2 + i/root2 ? Or it's just something we should know? I'm not exactly able to solve root of i

i^(1/2) = a + ib
i = (a + ib)^2
i = a^(2) + 2abi - b^(2)
a^(2) - b^(2) = 0 , 2ab = 1

solve them simultaneously
 
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Well in this case, there isn't any hint. And I did get the answer by taking 0, but I'm not sure if that's right.

Is there any method to arrive at 1/root2 + i/root2 ? Or it's just something we should know? I'm not exactly able to solve root of i

may be then its okay.. but i cant guarantee it ..
 
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Ummm ok... so how would you do it ?
in this case i would have used somewhat similar values like 1 or 2 ...but there was one question in which i used pi/4 as initial value to get the answer .. (it ws a trig question) .. :p
 
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