Quadratic Formula and Imaginary Numbers

Quadratic Formula and Imaginary Numbers

Part 2

Multiple Choice

Simplify √-4

• 2i
• -2i
• 2
• 4i

Multiple Choice

Simplify √-81

• -√81
• -9i
• 9i
• 81i

Multiple Choice

Desean begins to use the quadratic formula to solve the following equation.

 $x^2-3x=9$  

Which expression shows a step in solving the above equation?

•  $\frac{3\pm\sqrt{45}}{2}$  

•  $\frac{-3\pm\sqrt{45}}{2}$  

•  $\frac{3\pm\sqrt{-27}}{2}$  

•  $\frac{-3\pm\sqrt{-27}}{2}$  

Multiple Choice

 $x^2-6x+34$  
What are the roots of the equation in a+bi form?

•  $3+5i$  

•  $3\pm5i^{ }$  

•  $6\pm10i$  

Multiple Choice

 $x^2-16x+80=0$  
What are the roots of the equation in a+bi form.

•  $16\pm8i$  

•  $16\pm8$  

•  $8\pm4i$  

•  $8\pm4$