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Homework Help: Polar form of complex numbers

  1. Apr 4, 2017 #1
    1. The problem statement, all variables and given/known data
    well this is not exactly a homework, i had an argument whith my teacher about my grade in a test, because i put a complex number in the form of R,theta and she claims that the form was costheta+isentheta, and i know that but i need to prove in a book that r,theta=costheta+isentheta

    2. The attempt at a solution
    she ditnt request, a solution or demostration just if someone knows a book about the fact, please help me, the matter is from a very good grade to a failure grade so this is important, thank you

    i truly believe i am right but the teacher want to screw me really bad and asked for evidence in a book
  2. jcsd
  3. Apr 4, 2017 #2


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    Science Advisor
    Gold Member
    2017 Award

    The correct equality would be r⋅e = r⋅(cos(θ)+i sin(θ)).
    I'm not sure exactly what you were asked for on the test.
  4. Apr 4, 2017 #3


    Staff: Mentor

    r,theta=costheta+isentheta makes no sense. As @FactChecker already said, the correct identity is ##re^{i\theta} = r(\cos(\theta) + i\sin(\theta))##
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