How do I use a sign chart to solve `x^2+1<0`?

Related questions

• What is an inequality?
• What is a sign chart?
• How do I use a sign chart to solve `x^2>4`?
• How do I use a sign chart to solve `2x^2-7x<=-3`?
• How do I use a sign chart to solve `x^2<4`?
• How do I use a sign chart to solve `4x^2<=28x`?
• How do I use a sign chart to solve `2x^2-7x> -3`?
• How do I use a sign chart to solve `x^2+5x-9<0`?
• How do I use a sign chart to solve `2< -16t^2+6<5`?
• How do I use a sign chart to solve `2x^2+5x-3>0`?