Results 1 to 2 of 2

Math Help - Equation with square roots

  1. #1
    Super Member
    Joined
    Mar 2006
    Posts
    705
    Thanks
    2

    Equation with square roots

    I was tutoring the other day on college alg. and I couldn't solve this one equation...

    (t-169)^(1/2) - (t+36)^(1/2) = 43

    Thank you.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by tttcomrader View Post
    I was tutoring the other day on college alg. and I couldn't solve this one equation...

    (t-169)^(1/2) - (t+36)^(1/2) = 43

    Thank you.
    Start by squaring:

    (t-169) + (t+36) - 2[(t-169)(t+36)]^{1/2} = 43^2

    rearrange:

    [(t-169)(t+36)]^{1/2} = 991 - t

    square again:

    (t-169)(t+36) = (t-991)^2

    which reduces to:

    1849 t - 988165=0

    Now the games we have played may have introduced spurious solutions
    so each solution has to be checked to see if it actualy solves the equation.
    Doing this we find that t=988165/1849 is not a solution of the given
    equation, so there are no solutions to the equation.

    Reassuringly when fed to quickmath (which IIRC is Mathematica powered)
    and Derive they both also report no solutions.

    RonL

    (check the algebra - it can be a bit error prone)
    Last edited by CaptainBlack; October 7th 2006 at 11:59 PM.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Prove an Equation involving Square Roots
    Posted in the Algebra Forum
    Replies: 4
    Last Post: June 11th 2011, 12:04 PM
  2. Replies: 2
    Last Post: February 2nd 2011, 07:12 PM
  3. Replies: 3
    Last Post: October 15th 2010, 06:32 PM
  4. Equation with square roots and logs
    Posted in the Algebra Forum
    Replies: 6
    Last Post: August 28th 2010, 04:58 PM
  5. square roots
    Posted in the Algebra Forum
    Replies: 3
    Last Post: December 16th 2007, 12:26 PM

Search Tags


/mathhelpforum @mathhelpforum