7. Compute the cube roots of $$z = -8$$. 8. Express each of the following complex numbers in polar form, and plot them in the complex plane, indicating magnitude and angle of each number: $$z = 1 + i\sqrt{3}$$ $$z = 3 + 4i$$ $$z = (\sqrt{3} + i^3)(1 - i)$$ $$z = -5$$ $$z = (1 + i\sqrt{3})^3$$ $$z = -5 - 5i$$ $$z = (1 + i)^5$$ $$z = \frac{1+i\sqrt{3}}{\sqrt{3}+i}$$
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The magnitude of $$z$$ is $$|z| = |-8| = 8$$. The argument of $$z$$ is $$\theta = \arg(-8) = \pi$$ (since -8 lies on the negative real axis). So, $$z = 8(\cos(\pi) + i\sin(\pi))$$. Show more…
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