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Use DeMoivre's Theorem to find.?

((1/2)+(√3/2))^5

1 Answer

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  • Anonymous
    1 decade ago
    Favorite Answer

    I am assuming that we need to find:

    (1/2 + i√3/2)^5.

    Note that:

    (1/2 + i√3/2)^5

    = [1/2 * (1 + i√3)]^5

    = 1/32 * (1 + i√3)^5.

    Then, in polar form:

    1 + i√3 = 2(cos π/3 + i sin π/3).

    Therefore:

    (1/2 + i√3/2)^5

    = 1/32 * (1 + i√3)^5

    = 1/32 * [2(cos π/3 + i sin π/3)]^5

    = 1/32 * 2^5 * [cos(5 * π/3) + i sin (5 * π/3)]

    = cos 5π/3 + i sin 5π/3

    = 1/2 - i√3/2. <== ANSWER

    I hope this helps!

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