9000031204
Level:
A
Find the absolute value of the complex number
\(z = \frac{2-\mathrm{i}}
{2+\mathrm{i}}\).
\(1\)
\(5\)
\(\frac{\sqrt{7}}
{5} \)
\(\frac{\sqrt{5}}
{5} \)
Complex numbers in algebraic and polar form
9000031205
Level:
A
Find the complex conjugate of \(z = \mathrm{i}^{5} - 3\mathrm{i}^{10}\).
\(3 -\mathrm{i}\)
\(- 3 -\mathrm{i}\)
\(- 3 + \mathrm{i}\)
\(3 + \mathrm{i}\)
9000031201
Level:
A
Given complex numbers \(z_{1} = 1 - 2\mathrm{i}\)
and \(z_{2} = 3 + 5\mathrm{i}\),
find \(z_{1}z_{2}\).
\(13 -\mathrm{i}\)
\(13 + \mathrm{i}\)
\(- 7 -\mathrm{i}\)
\(13 + 11\mathrm{i}\)
9000031207
Level:
B
Find the algebraic form of the complex number
\(z = 2\left (\cos \frac{3\pi }
{4} + \mathrm{i}\sin \frac{3\pi }
{4}\right )\).
\(-\sqrt{2} + \mathrm{i}\sqrt{2}\)
\(\sqrt{2} + \mathrm{i}\sqrt{2}\)
\(\sqrt{2} -\mathrm{i}\sqrt{2}\)
\(-\sqrt{2} -\mathrm{i}\sqrt{2}\)
9000031208
Level:
B
Find the polar form of the complex number
\(z = -3 + 3\mathrm{i}\).
\(3\sqrt{2}\left (\cos \frac{3\pi }
{4} + \mathrm{i}\sin \frac{3\pi }
{4}\right )\)
\(3\left (\cos \frac{\pi }{4} + \mathrm{i}\sin \frac{\pi }{4}\right )\)
\(3\left (\cos \frac{5\pi }
{4} + \mathrm{i}\sin \frac{5\pi }
{4}\right )\)
\(3\sqrt{2}\left (\cos \frac{7\pi }
{4} + \mathrm{i}\sin \frac{7\pi }
{4}\right )\)
9000031206
Level:
A
Find the opposite number to the complex number
\(z = \frac{1+\mathrm{i}}
{1-\mathrm{i}}\).
\(-\mathrm{i}\)
\(1\)
\(- 1\)
\(\mathrm{i}\)
9000031203
Level:
A
Find the real part of the complex number
\(z = \frac{2-\mathrm{i}}
{2+\mathrm{i}}\).
\(0.6\)
\(0.8\)
\(- 0.8\)
\(1\)