Prove the following statement by contradiction method. p: The sum of an irrational number and a rational number is irrational
Prove the following statement by contradiction method. p: The sum of an irrational number and a rational number is irrational

Solution:

Let’s say that p is false, as sum of an irrational no. and a rational no. is irrational.

Let \sqrt{\lambda } is irrational and n is rational no.

\sqrt{\lambda } + n = r

\sqrt{\lambda } = r - n

But, it is known that \sqrt{\lambda } is irrational whereas (r-n) is rational which is a contradiction.

So here, our assumption is False.

As a result, P is true.