Results 1 to 4 of 4

Math Help - example of irrational + irrational = rational

  1. #1
    Junior Member
    Joined
    Jul 2009
    Posts
    68

    Question example of irrational + irrational = rational

    plzz give me examples when two DIFFERENT irrational numbers add up to form a rational number.

    a + b = c where a and b are two different irrational numbers and c is a rational numbers.

    i will be very much helpful if i get more than one example. plzz help thanks in advance.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    Joined
    Dec 2009
    From
    1111
    Posts
    872
    Thanks
    3
    Quote Originally Posted by saha.subham View Post
    plzz give me examples when two DIFFERENT irrational numbers add up to form a rational number.

    a + b = c where a and b are two different irrational numbers and c is a rational numbers.

    i will be very much helpful if i get more than one example. plzz help thanks in advance.
    Dear saha,

    Take any irrational number and it's negetive,

    e.g; a=\sqrt{2}~and~b=-\sqrt{2}

    Then, \sqrt{2}-\sqrt{2}=0\in{Q}

    Hope this will help you.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Mar 2010
    Posts
    20
    One more example:


    a=\sqrt{2}~and~b=1-\sqrt{2}<br />

    \sqrt{2}+1-\sqrt{2}=1\in{Q}<br />


    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor

    Joined
    Apr 2005
    Posts
    15,373
    Thanks
    1314
    Quote Originally Posted by MJ* View Post
    hi earboth....i dont think so thats true..22/7 is an irrational number ;it is infact pi. (3.1411592...)

    And if u ay that irrational numbers cant be expressed in form of fractions; then sqrt(2) wud not have been an irrtional number;coz it can be expressed in fractional form sqrt(2)/1

    for reference see:
    Pi - Wikipedia, the free encyclopedia
    Normally I wouldn't get too rough with people who respond to questions they have no clue about but posting a reference to Wikipedia that you didn't even bother to read carefully yourself enrages me.

    Wikipedia does NOT say that \pi is equal to "22/7". It lists that as one of many rational approximations to \pi.

    A number is rational if and only if it can be written as a fraction with integer numerator and denominator- that is often used as the definition of "rational number". Saying that \sqrt{2}= \sqrt{2}{1} does NOT make it a rational number because the numerator is not an integer.

    \pi is irrational, 22/7 is rational. They are NOT equal, they are "close"- and not that very close. 22/7= 3.142857142857... and differs from \pi in just the third decimal place.
    Last edited by CaptainBlack; April 5th 2010 at 12:25 AM. Reason: I have not deleted this because it may be useful in general, the rest of the posts on the original nonsense deleted
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 3
    Last Post: July 19th 2010, 05:04 PM
  2. Replies: 2
    Last Post: January 31st 2010, 05:40 AM
  3. Replies: 7
    Last Post: January 29th 2009, 03:26 AM
  4. 1/3 - RATIONAL OR IRRATIONAL??
    Posted in the Number Theory Forum
    Replies: 3
    Last Post: December 20th 2008, 03:37 AM
  5. Between a rational and a irrational
    Posted in the Calculus Forum
    Replies: 3
    Last Post: November 3rd 2008, 01:18 PM

Search Tags


/mathhelpforum @mathhelpforum