Results 1 to 10 of 10

Math Help - quadratic formula

  1. #1
    Junior Member
    Joined
    Aug 2008
    Posts
    32

    Exclamation quadratic formula

    2y^2+2y+1=0
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    Joined
    Jun 2008
    Posts
    792
    The quadratic formula is:

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

    What are a, b, and c? Well, you should know that:

    2y^2+2y+1 = ay^2 + by + c
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Rhymes with Orange Chris L T521's Avatar
    Joined
    May 2008
    From
    Chicago, IL
    Posts
    2,844
    Thanks
    3
    Quote Originally Posted by Chop Suey View Post
    The quadratic formula is:

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

    What are a, b, and c? Well, you should know that:

    2y^2+2y+1 = ay^2 + by + c
    Quote Originally Posted by Peyton Sawyer View Post
    2y^2+2y+1=0
    Just keep in mind that you will get complex [imaginary] solutions since the discriminant b^2-4ac<0. Note that \sqrt{-1}=i

    --Chris
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Junior Member
    Joined
    Aug 2008
    Posts
    32
    my answers arnt even close to these


    a. {( √3)/2}


    b. { -1, 0 }


    c. {(1 √3)/2}


    d. {(-1 √3)/2}


    e. { 0, 1 }
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Rhymes with Orange Chris L T521's Avatar
    Joined
    May 2008
    From
    Chicago, IL
    Posts
    2,844
    Thanks
    3
    Quote Originally Posted by Peyton Sawyer View Post
    my answers arnt even close to these


    a. {( √3)/2}


    b. { -1, 0 }


    c. {(1 √3)/2}


    d. {(-1 √3)/2}


    e. { 0, 1 }
    Just check and make sure you typed out the equation correctly. I think you have a missing minus sign somewhere. The way you gave us the equation implied that there was no real solution. If this equation you gave us is correct, then none of these choices are correct.

    --Chris
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Junior Member
    Joined
    Aug 2008
    Posts
    32
    this is the original

    2y^2+ 2y=1
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Super Member
    Joined
    Jun 2008
    Posts
    792
    In this case, you rearrange it to:
    2y^2 + 2y - 1 = 0

    And use the quadratic formula to find the two roots.
    Follow Math Help Forum on Facebook and Google+

  8. #8
    Senior Member
    Joined
    Feb 2008
    From
    Berkeley, Illinois
    Posts
    364
    Answer is d.

    I need to build an extra piece on the lesson here:

    Quadratic Equation

    But you can follow the math 1/2 way down and see that you get to:

    -2 \sqrt{12}/4

    Then Factor out a 2 from the top, which, for the second term is the simplifying the square root.
    Follow Math Help Forum on Facebook and Google+

  9. #9
    Junior Member
    Joined
    Aug 2008
    Posts
    32
    okay i got

    -1 plus/minus sq root 3/2
    Follow Math Help Forum on Facebook and Google+

  10. #10
    Super Member
    Joined
    Jun 2008
    Posts
    792
    \frac{-1\pm\sqrt{3}}{2}
    Then yes, you are right.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Using the quadratic formula
    Posted in the Algebra Forum
    Replies: 7
    Last Post: July 25th 2011, 01:51 PM
  2. Quadratic Formula
    Posted in the Algebra Forum
    Replies: 5
    Last Post: January 18th 2011, 12:40 PM
  3. quadratic formula
    Posted in the Algebra Forum
    Replies: 7
    Last Post: June 2nd 2010, 04:01 PM
  4. which quadratic formula do I use
    Posted in the Algebra Forum
    Replies: 1
    Last Post: November 7th 2008, 12:00 AM
  5. Quadratic Formula
    Posted in the Algebra Forum
    Replies: 2
    Last Post: November 6th 2007, 04:19 AM

Search Tags


/mathhelpforum @mathhelpforum