Complex Number Equations

Discussion in 'Geometry and Trigonometry' started by nycmathguy, Feb 27, 2022.

  1. nycmathguy

    nycmathguy

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    Section 6.6

    Can you do 91 and 93 as a guide for me to do a few more? Thank you.

    Screenshot_20220225-174758_Samsung Notes.jpg
     
    nycmathguy, Feb 27, 2022
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  2. nycmathguy

    MathLover1

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    91
    \(x^4+16i=0\)

    \(x^4=-16i\)

    [​IMG]

    [​IMG]

    solutions are:

    \(x = 2cos(π/8) - 2i *sin(π/8)\)

    \(x = 2cos(-π/8) + i *sin(-π/8)\)


    93

    \(x^3-(1-i)=0\)

    \(x^3=(1-i)\)

    [​IMG]

    [​IMG]
     
    Last edited: Feb 27, 2022
    MathLover1, Feb 27, 2022
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  3. nycmathguy

    nycmathguy

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    nycmathguy, Feb 27, 2022
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  4. nycmathguy

    nycmathguy

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    IMG_20220227_190446.jpg

    IMG_20220227_190453.jpg

    For 92 and 94, I need a step by step solution starting where I got stuck. Thank you. This completes Chapter 6 for us. I was going to skip Chapters 7 through 9 but decided that this is a bad idea. Chapter 7 begins next Friday. Back to work tomorrow. My weekend is over.

    IMG_20220227_190509.jpg

    IMG_20220227_190520.jpg
     
    nycmathguy, Feb 28, 2022
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  5. nycmathguy

    MathLover1

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    88.
    from here
    [​IMG]

    [​IMG]

    90.
    [​IMG]
    that is real solution, but we also have two complex solutions

    [​IMG]
    [​IMG]

    92.
    x^6+64*i=0
    x^6= -64*i

    For z^n=a the solutions are :

    [​IMG]

    k=0,1,..... ,n-1
    for n=6, a=-64i

    substituting values for a, n, and k you will get following complex solutions:

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]


    94. doing this one using same method as in 92, solutions will be

    [​IMG]
    [​IMG]
    [​IMG]

    [​IMG]
     
    MathLover1, Feb 28, 2022
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  6. nycmathguy

    nycmathguy

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    I don't understand this complex equation stuff. I never studied this material back in my college days. Looks terribly advanced for precalculus students. What is the name of the course that goes into great detail concerning such equations? I took precalculus back in 1993. The professor did not teach this stuff.
     
    nycmathguy, Feb 28, 2022
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