Question

Q. 9 Prove that 3 + 2 √7 us an irrational.

OR

Prove that √5 is an irrational.​

Answer 1

Step-by-step explanation:

Let us assume that 3+2√7 is rational

Then,

3+2√7=a/b where a and b are co primes

=> 2√7=a/b+3=(a+3b)/b

=> √7=(a+3b)/2b

We know that √7 is a irrational no and cannot be expressed i the form p/q, this proves the above statement wrong

The contradiction has arisen due to our wrong assumption that 3+2√7 is rational

=>3+2√7 is irrational