Question

1. Classify the following number as rational or irrational: (I) 2-√5​

Answer 1

Answer:

hey there

2-√5 is an irrational because here √5 is non perfect square it does not comes out from the root here is the proof

let 2-√5 be a rational number

2-√5 = Q (rational number is also represented by Q sign)

(2-√5)square = Q square

2 square +√5square -2 * 2*√5 = Q square (using formula( a -b ) square

4 + 5- 4√5 = Q square

9 - Q square = 4√5

9-Q square /2 = 4√5/2

9 -Q square = 2√5

hence our contradiction is wrong because when a rational number is dived by a rational number then the quotient is always ia rational number and here we get 2-√5 which is irrational

hence it is proved 2-√5 is an irrational number

hope it's help

Step-by-step explanation:

-from ABHI

Answer 2

Answer:

$\huge \underline \mathbb \green{Answer}$

$2 - \sqrt{5} =2 - 2.2360679............... \\=0.2360679................. \\ =non \: terminating \: non \: repeating \: \\ =Irrational$