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AmTran_Bus
 one year ago
Complex numbers
AmTran_Bus
 one year ago
Complex numbers

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AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1If Z=x+2iy, then find Re(z*) Where z=x+iy is the formula and x=Re(z) and y=IM(z)

AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1Re= real , IM=imag.

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.4\(z^*\) is obtained by reflecting the complex number over real axis it is called the conjugate of \(z\)

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.4when you reflect something over real axis, notice that the real component is not changed

AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1Here is how it says to do it: Re(z*) =Re(x2iy) =x. Can you help me understand it that way?

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.4just enter the part that is not attached to \(i\)

AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1I thought the same thing until part B that wants Re(z^2). I know the right answer for it but cant get it.

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.4z = x+2iy z^2 = (x+2iy)^2 = ?

AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1But I thought it only wanted the real part. If you square all of it for this one, why did you only worry about the x in the other and not the imaginary 2iy in the other one?

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.4because they are asking just the real part

AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1Yea, so why is it not z^2, so z=x, so z^2 = x^2?

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.4z is not x z is x+2iy

AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1So what does the Re they specifify there mean?

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.4to find the real part of z^2, first you need to find z^2

AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1So can you let me work through it real quick?

AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1So I need (x+2iy)^2 first, which gives x^2+4iy4y? is that right?

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.4(x+2iy)^2 = x^2 + 4iy  4y^2

AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1How is the last part that?

AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1I thought 2iy*2iy was 4i^2*y^2 Or 4y^3 Oh I understand.

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.4(2iy)^2 = 4i^2y^2 = 4y^2

AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1Oh so x^24y^2 is all the non imaginary stuff.

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.4\(z = x+i2y\) \(z^2 = (x+2iy)^2 = \color{red}{x^24y^2} + i\color{purple}{4y}\)

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.4yes x^24y^2 is the real part

AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1THANK YOU x1,000,000,000

AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1Wait, why does the book sayx^2+4ixy4y^2? Where did the x in the 4ixy come from? @ganeshie8

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.4right, \(z = x+i2y\) \(z^2 = (x+2iy)^2 = \color{red}{x^24y^2} + i\color{purple}{4xy}\)

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.4we're just using the identity \[\large (\heartsuit + \spadesuit)^2~~ =~~ \heartsuit^2 + 2\heartsuit\spadesuit + \spadesuit^2 \]

AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1dw:1440213734204:dw Sorry I'm so slow

ganeshie8
 one year ago
Best ResponseYou've already chosen the best response.4dw:1440213819660:dw

AmTran_Bus
 one year ago
Best ResponseYou've already chosen the best response.1yeppers. You came through again.
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