Complex numbers in algebraic and polar form

9000031208

Level: 
B
Find the polar form of the complex number \(z = -3 + 3\mathrm{i}\).
\(3\sqrt{2}\left (\cos \frac{3\pi } {4} + \mathrm{i}\sin \frac{3\pi } {4}\right )\)
\(3\left (\cos \frac{\pi }{4} + \mathrm{i}\sin \frac{\pi }{4}\right )\)
\(3\left (\cos \frac{5\pi } {4} + \mathrm{i}\sin \frac{5\pi } {4}\right )\)
\(3\sqrt{2}\left (\cos \frac{7\pi } {4} + \mathrm{i}\sin \frac{7\pi } {4}\right )\)

9000031209

Level: 
B
Given complex numbers \(z_{1} = 2\sqrt{2}\left (\cos \frac{\pi }{4} + \mathrm{i}\sin \frac{\pi }{4}\right )\) and \(z_{2} = \sqrt{2}\left (\cos \frac{7\pi } {4} + \mathrm{i}\sin \frac{7\pi } {4}\right )\), find the product \(z_{1}z_{2}\).
\(4\)
\(4\mathrm{i}\)
\(- 4\mathrm{i}\)
\(- 4\)

9000031210

Level: 
B
Given complex numbers \(z_{1} = 2\sqrt{3}\left (\cos \frac{\pi }{6} + \mathrm{i}\sin \frac{\pi }{6}\right )\) and \(z_{2} = \sqrt{3}\left (\cos \frac{4\pi } {3} + \mathrm{i}\sin \frac{4\pi } {3}\right )\), find the quotient \(\frac{z_{1}} {z_{2}} \).
\(-\sqrt{3} + \mathrm{i}\)
\(\sqrt{3} -\mathrm{i}\)
\(\sqrt{3} + \mathrm{i}\)
\(-\sqrt{3} -\mathrm{i}\)

9000034807

Level: 
B
Find the polar form of the complex number \(z = 2\mathrm{i}\).
\(2\left (\cos \frac{\pi }{2} + \mathrm{i}\sin \frac{\pi }{2}\right )\)
\(\sqrt{2}\left (\cos \frac{\pi }{2} + \mathrm{i}\sin \frac{\pi }{2}\right )\)
\(\cos \frac{\pi }{2} + \mathrm{i}\sin \frac{\pi }{2}\)
\(2\left (\cos 0 + \mathrm{i}\sin 0\right )\)

9000034809

Level: 
B
Given complex numbers \(z_{1} = 2\left (\cos \frac{\pi }{6} + \mathrm{i}\sin \frac{\pi }{6}\right )\) and \(z_{2} = \sqrt{3}\left (\cos \frac{4\pi } {3} + \mathrm{i}\sin \frac{4\pi } {3}\right )\), find the angle in the polar form of the product \(z_{1}z_{2}\).
\(\frac{3\pi } {2}\)
\(\frac{2} {9}\pi \)
\(\frac{5} {9}\pi \)
\(3\pi \)

9000034810

Level: 
B
Given complex numbers \(z_{1} = 2\left (\cos \frac{\pi }{4} + \mathrm{i}\sin \frac{\pi }{4}\right )\) and \(z_{2} = \sqrt{2}\left (\cos \frac{7\pi } {4} + \mathrm{i}\sin \frac{7\pi } {4}\right )\), find the angle in the polar form of the quotient \(\frac{z_{1}} {z_{2}} \).
\(\frac{\pi } {2}\)
\(- \frac{\pi } {2}\)
\(-\frac{3} {2}\pi \)
\(\frac{3} {2}\pi \)

9000035704

Level: 
B
Find the polar form of the complex number \( A \) graphed in the complex plane as shown in the picture.
\(z = 2\sqrt{2}\left (\cos \frac{3\pi } {4} + \mathrm{i}\sin \frac{3\pi } {4}\right )\)
\(z = 2\sqrt{2}\left (\cos \frac{\pi }{4} -\mathrm{i}\sin \frac{\pi }{4}\right )\)
\(z = 2\sqrt{2}\left (-\cos \frac{\pi }{4} + \mathrm{i}\sin \frac{\pi }{4}\right )\)
\(z = 2\sqrt{2}\left (\cos \frac{5\pi } {4} + \mathrm{i}\sin \frac{5\pi } {4}\right )\)

9000035805

Level: 
B
Given the complex numbers \[ \text{$a = 2\left (\cos \frac{2\pi } {3} + \mathrm{i}\sin \frac{2\pi } {3}\right )$, $b = \sqrt{2}\left (\cos \frac{3\pi } {4} + \mathrm{i}\sin \frac{3\pi } {4}\right )$,} \] find the product \(ab\).
\(2\sqrt{2}\left (\cos \frac{17\pi } {12} + \mathrm{i}\sin \frac{17\pi } {12}\right )\)
\(2\sqrt{2}\left (\cos \frac{\pi }{2} + \mathrm{i}\sin \frac{\pi }{2}\right )\)
\(2\sqrt{2}\left (\cos \frac{5\pi } {7} + \mathrm{i}\sin \frac{5\pi } {7}\right )\)
\(2\sqrt{2}\left (\cos \frac{5\pi } {12} + \mathrm{i}\sin \frac{5\pi } {12}\right )\)