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Задача Задача №2611980
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Аноним
10 января 2025 19:22 · публичный вопрос
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Аноним

(1-i)³

Ответ нейросети
10 января 2025 19:22

To calculate \((1 - i)^3\), we can use the binomial theorem or expand it directly.

  1. First, we can expand \((1 - i)^3\) using the binomial expansion formula:

\[ (a - b)^n = \sum_{k=0}^{n} \binom{n}{k} a^{n-k} (-b)^k \]

In our case, \(a = 1\), \(b = i\), and \(n = 3\):

\[ (1 - i)^3 = \sum_{k=0}^{3} \binom{3}{k} (1)^{3-k} (-i)^k \]

Calculating the terms in the expansion:

  • For \(k = 0\): \(\binom{3}{0}(1)^{3}(−i)^{0} = 1\)

  • For \(k = 1\): \(\binom{3}{1}(1)^{2}(−i)^{1} = 3 \cdot (-i) = -3i\)

  • For \(k = 2\): \(\binom{3}{2}(1)^{1}(−i)^{2} = 3 \cdot (-1) = -3\)

  • For \(k = 3\): \(\binom{3}{3}(1)^{0}(−i)^{3} = 1 \cdot (-i^3) = 1 \cdot i = i\)

Now combine these results:

\[ (1 - i)^3 = 1 - 3i - 3 + i \]

Combine the real and imaginary parts:

\[ = (1 - 3) + (-3i + i) = -2 - 2i \]

Therefore, the answer is:

\[ \boxed{-2 - 2i} \]