Question

Find the product of $\sqrt{2}-1$ with its conjugate

• A. $1$
• B. $-1$
• C. $2$
• D. $-2$

Answer 1

The correct option is A $1$

The conjugate $\sqrt{2}-1$ is $\sqrt{2}+1$
$(\sqrt{2}-1)(\sqrt{2}+1)=2-1=1$