Question

how to know if a number is irrational

Answer 1

irrational numbers are the ones that can't be written as a fraction

Answer 2

example?

Answer 3

sqrt(2) is an example. It can't be expressed as a fraction a/b where a and b are integers.

Answer 4

infinite numbers, like Pi, or the numbers that don't have a square root like 2

Answer 5

i need better example

Answer 6

What is wrong with sqrt(2)? Do you not understand why it's not rational?

Answer 7

is it because 2*2=4

Answer 8

sqrt(2) is a number that when multiplied by itself gives 2.
As in: \[\sqrt{2}\]

Answer 9

so its like 2*1

Answer 10

No. When muliplied by itself:
sqrt(2) * sqrt(2) = 2.
One solution to the equation x^2 = 2

Answer 11

okay i need a better example i dont under stand this

Answer 12

an irrational number can be either an INFINITE NUMBER, like Pi

Answer 13

or a number without a square root, like 5

Answer 14

the sqaure root of somthing has to to make a square right?

Answer 15

perfect square

Answer 16

Saying pi is infinite doesn't send the right message. It's irrational because it has an infinite decimal expression without a pattern.
You know a number is irrational if you can't write it as a fraction

Answer 17

like and improper fraction?

Answer 18

witch number is irrational \[\sqrt{121}\sqrt{150\sqrt{400\sqrt{1,000,000}}}\]

Answer 19

Simplify each of them. LIke what is sqrt(1000000) and then keep doing that until you reach a point where you can't take the square root because yu don't have a perfect square

Answer 20

is it 1000000