Solve for x x^2+1>=0

$x^{2} + 1 \geq 0$

Subtract $1$ from both sides of the inequality.

$x^{2} \geq - 1$

Since the left side has an even power, it is always positive for all real numbers for any value of $x$ .

All real numbers

The result can be shown in multiple forms.

All real numbers

Interval Notation:

$(- \infty, \infty)$