Finding Equations Given Complex Roots

Which of the following would be a root with 3i?

• 3i²

• -3i

• 3i

• -3i²

Which of the following would be the correct factored form with roots 2, 5i, and 6?

• (x-6)(x-2)(x+5i)(x-5i)

• (x+6)(x+2)(x+5i)

• (x-6)(x-2)(x-5i)

• (x+6)(x+2)(x-5i)

If a+bi is a root of a polynomial, then _______ is also a root.

• i²

• a-bi

• a+bi

• -i²

Write a polynomial function of least degree with integral coefficients that has the given zeros.

• A

• B

• C

• D

x² - 5x + 10 = 0

• (5 - i√15)/2  ,  (5 + i√15)/2

• (5 - √15)/2  ,  (5 + √15)/2

• (5 - i√65)/2  ,  (5 + i√65)/2

• (5 - √65)/2  ,  (5 + √65)/2

Solve x² - 5x + 10 = 0

• (5 - i√15)/2  ,  (5 + i√15)/2

• (5 - √15)/2  ,  (5 + √15)/2

• (5 - i√65)/2  ,  (5 + i√65)/2

• (5 - √65)/2  ,  (5 + √65)/2

Solve for x: 3x² - 6x + 6 = 0

• x = 1± i

• x = 3, -6

• x = 4.8, 2.7

• Undefined

Solve for x: x² - 5x + 8 = 0

• x = (-5±i√7)/2

• x = (5±i√7)/2

• x = (8±i√7)/2

• x = (5±√57)/2

Solve for x: x² - 3x + 10 = 0

• x = -3±i√31

• x = (3±√49)/2

• x = 5, -2

• x = (3±i√31)/2

x² - 5x + 10 = 0

• (5 - i√15)/2  ,  (5 + i√15)/2

• (5 - √15)/2  ,  (5 + √15)/2

• (5 - i√65)/2  ,  (5 + i√65)/2

• (5 - √65)/2  ,  (5 + √65)/2