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0213

  • 11 months ago

Could someone walk me through this question and explain to me what happens. I have been working on it for 7 hours. I don't understand my prof and I might fail the class and I want to cry. Its solving a quadratic equation that had complex numbers

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  1. 0213
    • 11 months ago
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    \[2x^2-ix-2+i=0\]

  2. DragonFlame
    • 11 months ago
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    :/ Sorry... I can't help..

  3. 0213
    • 11 months ago
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    :'(

  4. DragonFlame
    • 11 months ago
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    @jdoe0001

  5. jdoe0001
    • 11 months ago
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    tried using the quadratic formula yet?

  6. DragonFlame
    • 11 months ago
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    Phew! GO JDOE!

  7. 0213
    • 11 months ago
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    I tried it, i solved it but i got the wrong answers. I tried it over and over again. I looked up videos, still wrong answer

  8. jdoe0001
    • 11 months ago
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    \(\large \begin{array}{llll} {\color{red}{ 2}}x^2&{\color{blue}{ -i}}x&{\color{green}{ -2+i}}=0\\ \uparrow &\ \uparrow &\quad \uparrow \\ {\color{red}{ a}}&\ {\color{blue}{ b}}&\quad {\color{green}{ c}} \end{array}\\ \quad \\ \bf x=\cfrac{i\pm\sqrt{i^2-4(2)(-2+i)}}{2(2)}\implies x=\cfrac{i\pm\sqrt{-1-8(-2+i)}}{2(2)}\\ \quad \\ x=\cfrac{i\pm\sqrt{-1+16-8i}}{2(2)}\implies x=\cfrac{i\pm\sqrt{15-8i}}{4}\)

  9. 0213
    • 11 months ago
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    ok..got that

  10. jdoe0001
    • 11 months ago
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    well.. that's.... as far as I can see it going... what does your answer say?

  11. 0213
    • 11 months ago
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    x=1 and x=-1+0.5i

  12. jdoe0001
    • 11 months ago
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    hmmm I don't see it simplifying ... to that

  13. 0213
    • 11 months ago
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    :(

  14. RaphaelFilgueiras
    • 11 months ago
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    |dw:1389574709566:dw|

  15. RaphaelFilgueiras
    • 11 months ago
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    http://en.wikipedia.org/wiki/Ruffini's_rule

  16. 0213
    • 11 months ago
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    how did u do that

  17. RaphaelFilgueiras
    • 11 months ago
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    that is an algorithm

  18. 0213
    • 11 months ago
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    please explain...never learned that

  19. RaphaelFilgueiras
    • 11 months ago
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    |dw:1389575164382:dw|

  20. 0213
    • 11 months ago
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    wait...is this like synthetic division

  21. RaphaelFilgueiras
    • 11 months ago
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    |dw:1389575421091:dw|

  22. RaphaelFilgueiras
    • 11 months ago
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    this is the briot-ruffini algorithmm, i don't what is synthetic division

  23. 0213
    • 11 months ago
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    so in my question the root is 2?

  24. RaphaelFilgueiras
    • 11 months ago
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    no the root is one, the first coef in your polynomial is 2

  25. 0213
    • 11 months ago
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    how do i know what the root is?

  26. RaphaelFilgueiras
    • 11 months ago
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    one, was a easy root to see in that problem

  27. 0213
    • 11 months ago
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    oh. so if it had all 4...then it will be 2?

  28. 0213
    • 11 months ago
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    could u do it step by step and explain what you were doing at each step

  29. RaphaelFilgueiras
    • 11 months ago
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    |dw:1389575930097:dw|