Roots of Complex Numbers

What is the solution set of the equation  $x^2+9=0$  ?

•  $\left\{3,-3\right\}$  

•  $\left\{3i,\ -3i\right\}$  

•  $\left\{-3,-3i\right\}$  

•  $\left\{\ \right\}$  

Solve 
 $x^2+16=0$  

•  $x=\sqrt{-16}\ and\ x=-\sqrt{-16}$  

• x=4i and x= -4i

• x=8i and x = -8i

• x= 2.6 and x=-2.6

Simplify.

• -5i
• 5
• 5i
• -5

Simplify the following expression:

• 
• 
• 
• 

Solve the equation $3x^2+96=0$  

•  $x\ =\ \pm4\sqrt{2}$  

•  $x\ =\ \pm4i\sqrt{2}$  

•  $x\ =\ 2i\sqrt{4}$  

•  $x\ =\ \pm2\sqrt{4}$  

• 6i√5

• -8√5

• 8i√5

• -8i√5

What does i² = ?

• -1
• √-1
• 1
• -√1

• True

• False

Simplify:

3√-81

• -27

• 3i√3

• 27i

• 9i

x²+48 = 0

• 4i√3

• ±4√3

• ±4

• ±4i√3