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Mathematics: Post your doubts here!

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in the ms, it's written that u have to form 2 linear equations using real part and imaginary part. But i don't know how to do that :(

okok :p here you go:

3(a+ib) + 2i(a-ib) = 17+8i
Lets simplify the LHS first,
3a+3ib+ 2ai -2bi^2
3a+2b+(2a+3b)i = 17 +8i

now you get two linear equation:
3a+2b = 17 and 2a+3b = 8

hope you can solve now!! :)
 
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http://i.imgur.com/U8a8wmp.jpg

You basically have to eliminate either u or v from the equations and solve simultaneously. You could have also solved it by eliminating u like:
u + 2v = 2i - the first equation
Making u the subject:
u = 2i - 2v - (1)
As the other equation given is :
iu + v = 3 - (2)
Substitute (1) into (2):
i(2i-2v) + v = 3
-2 -2iv + v = 3
v - 2iv = 5
Making v the subject
v(1-2i) = 5
v= 5/(1-2i) - this is the second form given in the mark scheme



http://i.imgur.com/Ouotvyn.jpg

Edit: Er... if you were talking about graphing the argand diagrams question then it's lost on me too. Maybe these resources might help on graphing complex numbers in exponential form:
http://tutorial.math.lamar.edu/Extras/ComplexPrimer/Forms.aspx
http://www.intmath.com/complex-numbers/5-exponential-form.php
There are too many links; google "complex numbers +exponential form" for more resources
Thankyouuuuuuuuuuuuuu mannn.. I will see it later. mmm do we have to draw the arg diagram on a graph pper in the exam or what?
 
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