Results 1 to 2 of 2

Math Help - Rational algebraic expressions

  1. #1
    Junior Member
    Joined
    Dec 2005
    Posts
    58

    Rational algebraic expressions

    In a book stands that rational algebraic expression is {\sqrt 2} and that are not rational algebraic expression {\sqrt 2gh}, x+{\sqrt x}

    How can {\sqrt 2} be rational algebraic expression? Why isn't irrational?

    Why {\sqrt 2gh}, x+{\sqrt x} are irrational?
    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 DenMac21
    In a book stands that rational algebraic expression is {\sqrt 2} and that are not rational algebraic expression {\sqrt 2gh}, x+{\sqrt x}

    How can {\sqrt 2} be rational algebraic expression? Why isn't irrational?

    Why {\sqrt 2gh}, x+{\sqrt x} are irrational?
    A rational algebraic expression is an expressions which is of the form

    \frac{P(x)}{Q(x)},

    where P(x) and Q(x) are polynomials in x. Note this does not require
    that the coefficients in either polynomial be rational.

    With this definition {\sqrt 2} is a rational algebraic expression
    (even though {\sqrt 2} is not a rational number).

    Clearly with this definition  x+{\sqrt x} is not a rational algebraic expression.

    Assuming the remaining expression should be: \sqrt {2gh} and that g and h
    are polynomials then this is not a rational algebraic expression.

    RonL
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. [SOLVED] Algebraic expressions
    Posted in the Algebra Forum
    Replies: 7
    Last Post: March 20th 2011, 09:27 AM
  2. algebraic expressions
    Posted in the Algebra Forum
    Replies: 2
    Last Post: September 3rd 2009, 05:52 PM
  3. Rational Expressions and Radical Expressions
    Posted in the Algebra Forum
    Replies: 16
    Last Post: July 9th 2009, 09:29 PM
  4. algebraic expressions
    Posted in the Algebra Forum
    Replies: 4
    Last Post: January 22nd 2009, 07:04 AM
  5. algebraic expressions
    Posted in the Algebra Forum
    Replies: 9
    Last Post: January 19th 2009, 10:48 AM

Search Tags


/mathhelpforum @mathhelpforum