3.3 Complex Quadratics

Simplify the following:
(7-2i)(7+2i)

• 49
• 49-4i-4i²
• 53
• 14-4i-4i²

Simplify the following:
(3i+2)(6-3i)

• 21+12i
• 12-21i
• 18-6i
• 15i+12

Simplify the following:
(2x-8)²

• 4x-16
• 4x²-64
• 2x²-16x+64
• 4x²-32x+64

Simplify to lowest terms.

• x=(-3±5)/4
• x=(3±8)/2
• it is already in lowest terms
• x=(-6±8)/8

Simplify to lowest terms.

• x=1
• x=(3±7)/4
• x=10/-4
• x=(3±√43)/-4

Simplify to lowest terms. (Remember that i=√(-1))

• x=(6±6i)/4
• x=(3±3i)/2

Solve for x:
 $x^2-5x+8=0$ 

•  $x=\left\{\frac{-5\pm i\sqrt{7}}{2}\right\}$ 

•  $x=\left\{\frac{5\pm i\sqrt{7}}{2}\right\}$  

•  $x=\left\{\frac{8\pm i\sqrt{7}}{2}\right\}$  

•  $x=\left\{\frac{5\pm\sqrt{57}}{2}\right\}$  

Tags

CCSS.HSA-REI.B.4B

CCSS.HSN.CN.C.7

Solve the equation $3x^2+96=0$  

•  $\pm4\sqrt{2}$  

•  $\pm4i\sqrt{2}$  

•  $2i\sqrt{4}$  

•  $\pm2\sqrt{4}$  

Tags

CCSS.HSA-REI.B.4B

CCSS.HSN.CN.C.7

All imaginary roots comes in pairs.

• True
• False

Tags

CCSS.HSN.CN.C.7

CCSS.HSN.CN.C.9

Add: (2 + 3i) + (2 - 3i)

• 4 + 6i
• 4
• 13
• 4 + 9i

Tags

CCSS.HSN.CN.A.2