Results 1 to 3 of 3

Math Help - distance

  1. #1
    Junior Member
    Joined
    Aug 2007
    Posts
    58

    distance

    i'm trying to find the distance from (2,-7) to (5,1)

    i used the distance formula and got down to d=√(9+64)

    9+64=73, which obviously isn't a perfect square.


    9 and 64, however, ARE perfect squares

    sooo, is there a way i can use 3 and 8 to figure this out?

    or is my answer just gonna be
    √73

    ????
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    Joined
    Oct 2006
    Posts
    679
    Awards
    1

    Re:

    Re:
    Attached Thumbnails Attached Thumbnails distance-47.gif  
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,751
    Thanks
    651
    Hello, deathtolife04!

    i'm trying to find the distance from (2,-7) to (5,1)

    i used the distance formula and got down to d \,=\, \sqrt{9+64}

    9+64\,=\,73, which obviously isn't a perfect square.

    9 and 64, however, ARE perfect squares

    sooo, is there a way i can use 3 and 8 to figure this out? . . . . no

    or is my answer just gonna be \sqrt{73} ? . . . . yes

    This is a common thought . . . I wondered it about it myself (years ago).
    . . Then I took a closer look . . .

    The Distance Formula is: . d \;=\;\sqrt{\underbrace{(x_2-x_1)^2} + \underbrace{(y_2-y_1)^2}}
    . . . . . . . . . . . . . . . . . . . . . . . . . . \uparrow . . . . . . \uparrow
    . . . . . . . . . . . . . . . . . . . . . . . .
    square! . . .square!

    Get it? .We will always have two squares under the square root.

    The urge to "simplify" will always be there.

    But in general, \sqrt{a^2+b^2} is not equal to a+b.


    So we must wholeheartedly resist the temptation to "simplify", say, \sqrt{16 + 25}


    ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

    Personally, I think it's a dirty trick . . . daring us to blunder.

    I've accepted other injustices . . .
    . . that the word 'monosyllabic' has five syllables
    . . that the word 'lisp' has an 's' in it.

    So I've learned to cope with the dangerous Distance Formula.

    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: August 9th 2010, 03:03 PM
  2. distance
    Posted in the Algebra Forum
    Replies: 1
    Last Post: February 28th 2010, 11:04 PM
  3. Distance vs. Total distance
    Posted in the Calculus Forum
    Replies: 5
    Last Post: January 5th 2009, 03:22 PM
  4. least distance
    Posted in the Calculus Forum
    Replies: 1
    Last Post: November 12th 2008, 09:58 AM
  5. Distance Formula with given Distance but not X!
    Posted in the Pre-Calculus Forum
    Replies: 9
    Last Post: November 5th 2008, 09:48 PM

Search Tags


/mathhelpforum @mathhelpforum