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Math Help - quadratic formula problems

  1. #1
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    quadratic formula problems

    i have two problems that require using the quadratic formula to find the x-intercept of the parabola:

    1. f(x)=-32x^2-4x+1





    2. y=7x^2-9x+1


    I have to enter to xintercepts into an online homework program and it keeps on telling me im wrong!! please help!
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  2. #2
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    so ... what did you get, and what are the rules for entering your solution online?
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  3. #3
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    okay, for the first one i got -3- sq root 40/-2 and 6+ sq root 40/-2

    and the second one i got 10/32 and -1/8

    the format will allow me to use the sq root symbol and fractions but apparently my answers are wrong! i dont know what i am doing wrong!! if anyone can help me understand that would be awesome thanks!
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  4. #4
    A riddle wrapped in an enigma
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    Quote Originally Posted by lkl072186 View Post
    i have two problems that require using the quadratic formula to find the x-intercept of the parabola:

    1. f(x)=-32x^2-4x+1





    2. y=7x^2-9x+1


    I have to enter to xintercepts into an online homework program and it keeps on telling me im wrong!! please help!
    We don't know how you have to enter your answers online, but you do not have the correct solutions You should end up with x=1/8 and x=-1/4 for your first one.

    1.) -32x^2-4x+1=0

    x=\frac{-b \pm \sqrt{b^2-4ac}}{2a}

    x=\frac{4 \pm \sqrt{(-4)^2-4(-32)(1)}}{2(-32)}=\frac{4 \pm \sqrt{144}}{-64}=\frac{4 \pm 12}{-64} = \frac{1}{8} \ \ and \ \ -\frac{1}{4}

    Your second solution is wrong as well. Try it again.
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