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Math Help - Solve for x

  1. #1
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    Solve for x

    (x-2)(x^2 + 3x) + 5x - 3 = 0

    Any suggestions on how to solve for x? Thanks,

    Jim
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  2. #2
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    Quote Originally Posted by Jim Newt View Post
    (x-2)(x^2 + 3x) + 5x - 3 = 0

    Any suggestions on how to solve for x? Thanks,

    Jim
    0. Graph the funktion to get the number of x-intercepts.

    1. Expand the brackets:

    x^3+x^2-x-3=0

    2. Use Cardano's formula (kind of tricky) or

    3. Use Newton-Raphson method to get an approximate solution.

    4. There is only one real solution.

    5. For your confirmation only: x \approx 1.359304085
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  3. #3
    A riddle wrapped in an enigma
    masters's Avatar
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    Simplifies to x^3 + x^2 - x - 3 = 0

    No rational roots.

    One irrational root
    Two complex roots
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  4. #4
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    Thanks!
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  5. #5
    MHF Contributor Mathstud28's Avatar
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    Quote Originally Posted by earboth View Post
    0. Graph the funktion to get the number of x-intercepts.

    1. Expand the brackets:

    x^3+x^2-x-3=0

    2. Use Cardano's formula (kind of tricky) or

    3. Use Newton-Raphson method to get an approximate solution.

    4. There is only one real solution.

    5. For your confirmation only: x \approx 1.359304085
    Use a combination of intuitiveness and the intermediate value theorem to get a good guess to start Newton's method
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