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Math Help - [SOLVED] Quadratics setting on cacluator

  1. #1
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    [SOLVED] Quadratics setting on cacluator

    Hi,

    I am trying to work out some quadractic equations when I compare the my answer to the answer book it is wrong. I even typed in the exact example they gave me. My calculator screen is attached is it in the right settings?

    Thanks
    Attached Thumbnails Attached Thumbnails [SOLVED] Quadratics setting on cacluator-p260908_11.24-01-.jpg  
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  2. #2
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    Quote Originally Posted by TheHour View Post
    Hi,

    I am trying to work out some quadractic equations when I compare the my answer to the answer book it is wrong. I even typed in the exact example they gave me. My calculator screen is attached is it in the right settings?

    Thanks
    Why are you using a calculator to solve a quadratic equation? Just factor the thing or use the quadratic formula.
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  3. #3
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    I need the calculator for the formula


    When I substitute a, b and c the answer is I get on my calculator is different to the answer in the answer book I know the theory is correct. Would you like to see my workings

    Thanks
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  4. #4
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    Quote Originally Posted by TheHour View Post
    I need the calculator for the formula


    When I substitute a, b and c the answer is I get on my calculator is different to the answer in the answer book I know the theory is correct. Would you like to see my workings

    Thanks
    That would be nice.
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  5. #5
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    Here it is

    Thanks
    Attached Thumbnails Attached Thumbnails [SOLVED] Quadratics setting on cacluator-untitled.png  
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  6. #6
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    Quote Originally Posted by TheHour View Post
    Here it is

    Thanks
    Check your arithmetic!

    \frac{-5+\sqrt{17}}{2}=-.438

    \frac{-5-\sqrt{17}}{2}=-4.562
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  7. #7
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    So its my calculator as I worked out

    \frac{-5+\sqrt{17}}{2}

    \frac{-5-\sqrt{17}}{2}

    on my calculator and it gave me the results in the image above. The settings on the caluclator are in my first post, im sure I have reset the settings by mistake. Looks like my method is fine though just the working out wich wasn't even done by me

    Thanks
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  8. #8
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    Quote Originally Posted by TheHour View Post
    So its my calculator as I worked out

    \frac{-5+\sqrt{17}}{2}

    \frac{-5-\sqrt{17}}{2}

    on my calculator and it gave me the results in the image above. The settings on the caluclator are in my first post, im sure I have reset the settings by mistake. Looks like my method is fine though just the working out wich wasn't even done by me

    Thanks
    You have to be careful when you enter things in a calculator. You probablly did not pair all your parentheses. Try it this way:

    Be sure to put the entire numerator in parentheses before you divide by 2.

    My solutions in Post #6 are correct. What does your book say?
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  9. #9
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    You where correct as the answers say -0.438 or -4.562.

    While typing this I remember the way I am working it out I need brackets, im not typing it in as a fraction as you did, im just doing it as one line, doh. All fixed

    Many Thanks, for your help
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