Question

x² + 1 < 3

 

Answer 1

x=-1,1,0

 

Answer 2

\(x^2< 3-1\\ x^2< 2\\ \left[{}\begin{matrix}x< \sqrt{2}\\x>-\sqrt{2}\end{matrix}\right.=>-\sqrt{2}< x< \sqrt{2}\)

Answer 3

\(x^2+1< 3\)

\(x^2< 2\)

\(\Rightarrow-\sqrt{2}< x< \sqrt{2}\)

Answer 4

$x^2 + 1 < 3$

$⇔ x^2 - 2 < 0$

$⇔ -\sqrt{2} < x < sqrt{2}$