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2007-12-08 11:31:04 · 9 answers · asked by blue_eyed_woman_23 3 in Science & Mathematics Mathematics

9 answers

By itself - essentially it is an irrational number

sqrt8 --- 2 sqrt 2 ---- sqrt 2 is an irrational number (multiplying it by 2 makes no difference)

An essential characteristic of differentiating irrational and rational numbers are that irrational numbers don't seem to have an end....

2007-12-08 11:40:38 · answer #1 · answered by aloofnerd 3 · 0 0

sqrt of 8 = 2 sqrt of 2 irrational

2007-12-08 11:34:30 · answer #2 · answered by Dave aka Spider Monkey 7 · 0 0

It's equal to 2*√2 and √2 is irrational, so √8 is also
irrational.

2007-12-08 12:49:25 · answer #3 · answered by steiner1745 7 · 0 0

For any whole number A, unless A is a perfect square (i.e. unless A = B², with B a whole number also), √A is irrational.

8 = 2*2*2 is not a perfect square, so √8 is irrational.

2007-12-08 11:46:31 · answer #4 · answered by a²+b²=c² 4 · 0 0

suppose sqrt 8 is rational
then sqrt 8 = a/b , a,b=integer b is not 0 GCD(a,b)=1
square ; 8 = a^2/b^2
a^2 = 8*b^2
a^2 is an even number
if a is odd , a^2 is odd too.
therefore , a is even
so a = 2k , k=integer
a^2 = (2k)^2 =4k^2 = 8*b^2
k^2 = 2*b^2
in the same way, k is even
so k = 2n , n=integer
a^2 = 4k^2=4(2n)^2=4(4n^2)=16n^2 = 8b^2
therefore , 2*n^2=b^2
in the same way, b is even
so both a and b are even
therefore , GCD(a,b) is not 1
but GCD(a,b)=1
therefore, sqrt 8 is not rational
so sqrt 8 is irrational

2007-12-08 12:10:14 · answer #5 · answered by sothanaphan 2 · 1 0

It is irrational because the sqrt(8)=2(sqrt(2)).
the sqrt(2) is irrational

2007-12-08 11:34:50 · answer #6 · answered by cheeseywonder 1 · 0 0

For an expression ax^2+bx+c, the discriminant is b^2-4ac. b^2-4ac > 0 => 2 different rational suggestions b^2-4ac = 0 => precisely one rational answer b^2-4ac < 0 => 2 different irrational suggestions right here b^2-4ac = (-12)^2 - 4*a million*34 = a hundred and forty four - 136 = 8 that's greater advantageous than 0 for this reason this equation has 2 different rational suggestions.

2016-11-14 03:10:46 · answer #7 · answered by tameka 4 · 0 0

8 is not a perfect square; so the square root of 8 must be irrational

2007-12-08 11:49:50 · answer #8 · answered by Anonymous · 0 0

8 is not a perfect square so it would be irrational

2007-12-08 12:07:36 · answer #9 · answered by Anonymous · 0 0

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