Polynomials and Unity Roots

40 MCQs This test covers factorization of complex polynomials, the fundamental theorem of algebra, and solving quadratics by completing the square. It also covers building polynomials from given zeros, cube roots and fourth roots of unity with their properties, and the roots of numbers like -8, 64 and 625.

MCQs

40 questions · 35 min · 40 marks

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Sample questions

The first 5 of 40. Try each one, then tap to see the answer.

  1. Question 1

    A polynomial of degree n ≥ 1 has exactly how many roots in C?

    • An - 1
    • Bn
    • Cn + 1
    • D2n
    Show answer

    Answer: B

    This is the fundamental theorem of algebra.

  2. Question 2

    a^2 + 4b^2 factorizes over C as:

    • A(a - 2bi)(a + 2bi)
    • B(a - 4bi)(a + 4bi)
    • C(a + 2b)(a - 2b)
    • D(a - 2b)^2
    Show answer

    Answer: A

    a^2 - (2bi)^2 = a^2 + 4b^2.

  3. Question 3

    9a^2 + 16b^2 factorizes over C as:

    • A(3a - 16bi)(3a + 16bi)
    • B(9a - 4bi)(9a + 4bi)
    • C(3a - 4bi)(3a + 4bi)
    • D(3a + 4b)^2
    Show answer

    Answer: C

    (3a)^2 - (4bi)^2 = 9a^2 + 16b^2.

  4. Question 4

    z^2 + 4z + 5 factorizes as:

    • A(z - 2 + i)(z - 2 - i)
    • B(z + 4 + i)(z + 4 - i)
    • C(z + 2)(z + 2)
    • D(z + 2 + i)(z + 2 - i)
    Show answer

    Answer: D

    (z + 2)^2 - i^2 = z^2 + 4z + 5.

  5. Question 5

    z^2 + 6z + 13 factorizes as:

    • A(z - 3 + 2i)(z - 3 - 2i)
    • B(z + 3 + 2i)(z + 3 - 2i)
    • C(z + 3 + 4i)(z + 3 - 4i)
    • D(z + 6 + i)(z + 6 - i)
    Show answer

    Answer: B

    (z + 3)^2 - (2i)^2 = z^2 + 6z + 13.

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