what is an irrational number

Question

anonymous · Answer

an irrational number is any real number that cannot be expressed as a ratio a/b

jiteshmeghwal9 · Answer

These are the no. which have no exact value.
Eg :- $\large{\sqrt{4}}=2=\text{Rational}$
          $\large{\sqrt{3}=not\space exact=Irrational }$

experimentx · Answer

@Yahoo!  a/b of rational numbers

experimentx · Answer

woops!! sorry .. of integers

experimentx · Answer

@jiteshmeghwal9 do you know about transcendental numbers?

jiteshmeghwal9 · Answer

no

jiteshmeghwal9 · Answer

Wht are those ??

experimentx · Answer

transcendental numbers are also irrational numbers ... the irrational numbers you wrote are algebraic numbers.
like you can get sqrt(2) from x^2 - 2 = 0 <-- polynomials
but you can never get $ \pi $ or $ e $ from such polynomials with integer coefficients.
these are transcendental numbers.

jiteshmeghwal9 · Answer

Ok! i gt it now wht is $e$ since i do not know more than that this is a number :/

experimentx · Answer

hmm ... you can prove 'e' is irrational number, like you know for $ \sqrt 2 $ , this is quite easy. But proving $ \pi $ is irrational is difficult. also check these. http://en.wikipedia.org/wiki/Transcendental_number

experimentx · Answer

here is a proof that $ e $ is irrational number http://en.wikipedia.org/wiki/Proof_that_e_is_irrational

jiteshmeghwal9 · Answer

Thaanx !!!!

experimentx · Answer

my pleasure!!