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Prove that
(-1 + i√3)⁴(−1 - i√3)⁵=512ω²​

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Answer:

We can simplify this expression using Euler's formula, which states that for any real number x,

e^(ix) = cos(x) + i sin(x)

Let's start by writing (-1 + i√3) as a complex number in polar form:

-1 + i√3 = 2e^(i(2π/3))

Similarly, we can write (-1 - i√3) as:

-1 - i√3 = 2e^(-i(2π/3))

Now we can raise each of these complex numbers to the fourth and fifth powers, respectively:

(-1 + i√3)⁴ = (2e^(i(2π/3)))⁴ = 16e^(i(8π/3)) = 16e^(i(2π/3))

(-1 - i√3)⁵ = (2e^(-i(2π/3)))⁵ = 32e^(-i(10π/3)) = 32e^(i(2π/3))

Multiplying these two expressions together, we get:

(-1 + i√3)⁴(−1 - i√3)⁵ = 16e^(i(2π/3)) * 32e^(i(2π/3)) = 512e^(i(4π/3))

Now, we can use Euler's formula again to convert this expression back to rectangular form:

512e^(i(4π/3)) = 512(cos(4π/3) + i sin(4π/3)) = 512(-1/2 + i(-√3/2)) = 512ω²

where ω = e^(iπ/3) is a primitive cube root of unity. Therefore, we have shown that:

(-1 + i√3)⁴(−1 - i√3)⁵ = 512ω²

as desired.

Explanation:

answered
User Kamyar Ghasemlou
by
8.2k points

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