Express the Indicated Roots of Unity in Standard Form a $1+0 \mathrm{i}$

question 312

Multiple Choice

Express the indicated roots of unity in standard form a + bi.
-Seventh roots of unity

• A) \( 1+0 \mathrm{i} \)
• \[
• \begin{array}{l}
• \cos \frac{2 \pi}{7}+i \sin \frac{2 \pi}{7} \approx 0.62+0.78 i \\
• \cos \frac{4 \pi}{7}+i \sin \frac{4 \pi}{7} \approx-0.22+0.97 i \\
• \cos \frac{6 \pi}{7}+i \sin \frac{6 \pi}{7} \approx-0.90+0.43 i \\
• \cos \frac{8 \pi}{7}+i \sin \frac{8 \pi}{7} \approx-0.90-0.43 i \\
• \cos \frac{10 \pi}{7}+i \sin \frac{10 \pi}{7} \approx-0.22-0.97 i
• \end{array}
• \]
• B) \(\begin{array}{l}
• \text { } 1+0 i \\
• \cos \frac{2 \pi}{7}+i \sin \frac{2 \pi}{7} \approx 0.62+0.78 i \\
• \cos \frac{4 \pi}{7}+i \sin \frac{4 \pi}{7} \approx-0.22+0.97 \mathrm{i} \\
• \cos \frac{6 \pi}{7}+i \sin \frac{6 \pi}{7} \approx-0.90+0.43 \mathrm{i} \\
• \cos \frac{8 \pi}{7}+i \sin \frac{8 \pi}{7} \approx-0.90-0.43 \mathrm{i} \\
• \cos \frac{10 \pi}{7}+i \sin \frac{10 \pi}{7} \approx-0.22-0.97 \mathrm{i} \\
• \cos \frac{12 \pi}{7}+i \sin \frac{12 \pi}{7} \approx 0.62-0.78 \mathrm{i}
• \end{array}\)
• C) \( 1+0 i \)
• \[
• \begin{array}{l}
• \cos \frac{2 \pi}{7}+i \sin \frac{2 \pi}{7} \approx 0.62+0.78 i \\
• \cos \frac{4 \pi}{7}+i \sin \frac{4 \pi}{7} \approx-0.22+0.97 i \\
• \cos \frac{6 \pi}{7}+i \sin \frac{6 \pi}{7} \approx-0.90+0.43 i \\
• \cos \frac{8 \pi}{7}+i \sin \frac{8 \pi}{7} \approx-0.90-0.43 i \\
• \cos \frac{10 \pi}{7}+i \sin \frac{10 \pi}{7} \approx-0.22-0.97 \\
• \cos \frac{12 \pi}{7}+i \sin \frac{12 \pi}{7} \approx 0.62-0.78 i
• \end{array}
• \]
• D) \( 1+0 i \)
• \[
• \begin{array}{l}
• \cos \frac{\pi}{7}+i \sin \frac{\pi}{7} \approx 0.90+0.43 i \\
• \cos \frac{2 \pi}{7}+i \sin \frac{2 \pi}{7} \approx 0.62+0.78 i \\
• \cos \frac{3 \pi}{7}+i \sin \frac{3 \pi}{7} \approx 0.22+0.97 i \\
• \cos \frac{4 \pi}{7}+i \sin \frac{4 \pi}{7} \approx-0.22+0.97 \mathrm{i} \\
• \cos \frac{5 \pi}{7}+i \sin \frac{5 \pi}{7} \approx-0.62+0.78 \mathrm{i} \\
• \cos \frac{6 \pi}{7}+i \sin \frac{6 \pi}{7} \approx-0.90+0.43 \mathrm{i}
• \end{array}
• \]

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