Results 1 to 9 of 9

Math Help - Quadratics Review

  1. #1
    Member
    Joined
    Aug 2007
    Posts
    193

    Quadratics Review

    If anyone wouldnt mind, I would really appreciate it if someone would take a look at my work....I had to do this review, but I am not totally sure if I am doing these problems correctly..There are about 5 problems...you dont have to check them all, but I would really like to make sure that I am on the right track...thanks


    Follow Math Help Forum on Facebook and Google+

  2. #2
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    10,057
    Thanks
    369
    Awards
    1
    Quote Originally Posted by aikenfan View Post
    If anyone wouldnt mind, I would really appreciate it if someone would take a look at my work....I had to do this review, but I am not totally sure if I am doing these problems correctly..There are about 5 problems...you dont have to check them all, but I would really like to make sure that I am on the right track...thanks


    I don't have time to look at much, but for 1b) note that when you take the square root the LHS gets a \pm on it, so there are two solutions, not one. The rest of problem 1 is correct.

    -Dan
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Aug 2007
    Posts
    193
    Thank you for all of your help!
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    10,057
    Thanks
    369
    Awards
    1
    Quote Originally Posted by aikenfan View Post
    If anyone wouldnt mind, I would really appreciate it if someone would take a look at my work....I had to do this review, but I am not totally sure if I am doing these problems correctly..There are about 5 problems...you dont have to check them all, but I would really like to make sure that I am on the right track...thanks


    I get 3 zeros for 3a) and for 3b) I get x = 3 is exact.

    For 10 you can do this in a much simpler way, assuming you don't have to put the parabola in "standard form."

    A general form for a parabola is
    y = a(x - r_1)(x - r_2)
    where r_1 \text{ and }r_2 are the zeros of the parabola.

    So two possible answers would be:
    y = (x - 3)(x + 5) = x^2 + 2x - 15<-- Opens upward
    and
    y = -(x - 3)(x + 5) = -x^2 - 2x + 15<-- Opens downward

    -Dan
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Member
    Joined
    Aug 2007
    Posts
    193
    Thank you! Would 10 be correct the way it is, though? That is the way that we were taught to do them.
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Member
    Joined
    Aug 2007
    Posts
    193
    For the third zero on 3a) I get 2.115
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    10,057
    Thanks
    369
    Awards
    1
    Quote Originally Posted by aikenfan View Post
    Thank you! Would 10 be correct the way it is, though? That is the way that we were taught to do them.
    You lost a negative sign on the downward opening parabola. Otherwise, yes.

    -Dan
    Follow Math Help Forum on Facebook and Google+

  8. #8
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    10,057
    Thanks
    369
    Awards
    1
    Quote Originally Posted by aikenfan View Post
    For the third zero on 3a) I get 2.115
    Looks good to me.

    This is not the first time you have missed a zero on one of these. Make sure you are looking at enough of the x-axis that you are absolutely certain you have all of them.

    -Dan
    Follow Math Help Forum on Facebook and Google+

  9. #9
    Member
    Joined
    Aug 2007
    Posts
    193
    Thank you very much for all of the help!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Need help on Review
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: April 5th 2009, 10:53 PM
  2. Replies: 5
    Last Post: November 2nd 2008, 11:43 AM
  3. Conics Review
    Posted in the Algebra Forum
    Replies: 2
    Last Post: July 26th 2008, 02:36 PM
  4. Help with review
    Posted in the Pre-Calculus Forum
    Replies: 4
    Last Post: January 22nd 2008, 03:07 PM
  5. please help me with this exam review. thanks a lot.
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: October 26th 2007, 09:13 PM

Search Tags


/mathhelpforum @mathhelpforum