imaginary numbers

Simplify √-4

• 2i
• -2i
• 2
• 4i

Simplify √-81

• -√81
• -9i
• 9i
• 81i

• 2i√6

• 8i√3

• -2√6

• -2i√6

The imaginary number  $i$  is defined as

• -1

•  $\sqrt{-1}$  

•  $\sqrt{-4}$  

•  $\left(-1\right)^2$  

Which of the following is equivalent to  $\sqrt{-128}$ ?

•  $8\sqrt{2}$  

•  $8i$  

•  $-8\sqrt{2}$  

•  $8i\sqrt{2}$  

Solve.   x² = √-36

• x = ± 6
• x = 6i
• x = ± 6i
• x = i√6

Solve.
  x² = √-100

• x = 10i
• x = ± 10i
• x = ±10
• x = √10

Solve.   x² = √-40

• x = 4i√10
• x = ± 2√10
• x = ± 2i√10
• x = ± 10i√2

Solve.  
x² +12 = 5

• x = ± 49
• x = ± i√7
• x = ± √7
• x = ± 3.5i

Solve.    x² = √27

• x = ± 3√3
• x = ± 9√3
• x = 3i√3
• x = 3√9