for any two complex no. z1 and z2 prove that re(z1 z2) = re(z1) * re(z2) - im(z1) * im(z2) my incomplete soln- don't have any idea about it.
Last edited by saha.subham; May 29th 2011 at 08:00 AM. Reason: wrng question
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Originally Posted by saha.subham for any two complex no. z1 and z2 prove that re(z1 z2) = re(z1) + re(z2) - im(z1) * im(z2) my incomplete soln- don't have any idea about it. Start by saying that z1=a+ib and z2=c+id. If z=x+iy then: The real part of z is: Re(z)=x and the imaginary part is: Im(z)=y
So what is the real part of ?
Originally Posted by Prove It So what is the real part of ? ok i have edited the question after consulting with my friend, it seems i have to remove the last part from ur answer, can u please guide me?
You can write any complex number as , where is the real part of and is the imaginary part of . You have . If you're going to rewrite this as , what is (the real part of )?
Originally Posted by Prove It You can write any complex number as , where is the real part of and is the imaginary part of . You have . If you're going to rewrite this as , what is (the real part of )? How thus is in the form re(z1) * re(z2) - im(z1) * im(z2) ???
Because is the real part of , is the real part of , is the imaginary part of and is the imaginary part of .
Originally Posted by Prove It Because is the real part of , is the real part of , is the imaginary part of and is the imaginary part of . then it will be, x1x2 - y1y2, but how can i cancel out i(x1y2+ x2y1)??
You DON'T. You are asked merely to state the REAL part of , in other words, everything that's not attached to an .
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