1. **State the problem:** Calculate the value of $(-1+i)^{2i}$ where $i$ is the imaginary unit.
2. **Recall the formula:** For a complex number $z$ and a complex exponent $w$, we use the formula:
$$z^w = e^{w \log z}$$
where $\log z$ is the complex logarithm of $z$.
3. **Find the polar form of $z = -1 + i$:**
- Calculate the modulus:
$$r = |z| = \sqrt{(-1)^2 + 1^2} = \sqrt{1 + 1} = \sqrt{2}$$
- Calculate the argument (angle):
$$\theta = \arctan\left(\frac{1}{-1}\right) = \arctan(-1)$$
Since the point $(-1,1)$ is in the second quadrant, the angle is:
$$\theta = \pi - \frac{\pi}{4} = \frac{3\pi}{4}$$
4. **Express $z$ in polar form:**
$$z = r e^{i\theta} = \sqrt{2} e^{i \frac{3\pi}{4}}$$
5. **Calculate $z^{2i}$:**
$$(-1+i)^{2i} = \left(\sqrt{2} e^{i \frac{3\pi}{4}}\right)^{2i} = e^{2i \log \left(\sqrt{2} e^{i \frac{3\pi}{4}}\right)}$$
6. **Calculate the complex logarithm:**
$$\log \left(\sqrt{2} e^{i \frac{3\pi}{4}}\right) = \log \sqrt{2} + i \frac{3\pi}{4} = \frac{1}{2} \log 2 + i \frac{3\pi}{4}$$
7. **Substitute back:**
$$e^{2i \left( \frac{1}{2} \log 2 + i \frac{3\pi}{4} \right)} = e^{2i \cdot \frac{1}{2} \log 2 + 2i \cdot i \frac{3\pi}{4}} = e^{i \log 2 - 2 \cdot \frac{3\pi}{4}} = e^{i \log 2 - \frac{3\pi}{2}}$$
8. **Separate real and imaginary parts in the exponent:**
$$e^{i \log 2 - \frac{3\pi}{2}} = e^{- \frac{3\pi}{2}} \cdot e^{i \log 2}$$
9. **Express $e^{i \log 2}$ using Euler's formula:**
$$e^{i \log 2} = \cos(\log 2) + i \sin(\log 2)$$
10. **Final answer:**
$$(-1+i)^{2i} = e^{- \frac{3\pi}{2}} \left( \cos(\log 2) + i \sin(\log 2) \right)$$
This is the exact value in rectangular form.
Complex Power Fca766
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