show that z= (-1+√-3)³ / (2)³ is rational number
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Answer:
a + b)³ = (a + b)(a + b)(a + b)
In (-1+√3i)³ , a = -1 & b = i√3
(-1+√3i)³ = (-1 + i√3)(-1 + i√3)(-1 + i√3)
(-1+√3i)³ = (1 - 3 - 2i√3)(-1 + i√3)
(-1+√3i)³ = (-2 - 2i√3)(-1 + i√3)
(-1+√3i)³ = -2(1 + i√3)(-1 + i√3)
(-1+√3i)³ = -2 (-1 - 3)
(-1 + i√3)³ = -2 (-4)
(-1 + i√3)³ = 8
8=8/1
The number 8 is a rational number because it can be written as the fraction 8/1.
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