B

9000033806

Level: 
B
In the following list identify a true statement for the function \(i\colon y =\mathop{\mathrm{tg}}\nolimits x\), \(x\in \left ( \frac{\pi }{2}; \frac{3\pi } {2}\right )\).
The function \(i\) is increasing.
The function \(i\) is decreasing.
The function \(i\) is neither increasing nor decreasing.

9000034304

Level: 
B
Find the solution set of the following equation in the set of complex numbers. \[ x^{4} - 1 = 0 \]
\(\{1;\ -1;\ \mathrm{i};\ -\mathrm{i}\}\)
\(\{1 -\mathrm{i};\ -1 -\mathrm{i}\}\)
\(\{1 + \mathrm{i};\ -1 + \mathrm{i}\}\)
\(\{1 + \mathrm{i};\ 1 -\mathrm{i};\ -1 + \mathrm{i};\ -1 -\mathrm{i}\}\)

9000034305

Level: 
B
Solve the following equation in the set of complex numbers. \[ x^{4} + 16 = 0 \]
\(x_{1, 2} = \sqrt{2}(1\pm \mathrm{i}),\ x_{3, 4} = -\sqrt{2}(1\pm \mathrm{i})\)
\(x_{1, 2} = 1\pm \mathrm{i},\ x_{3, 4} = -1\pm \mathrm{i}\)
\(x_{1, 2} = 2(1\pm \mathrm{i}),\ x_{3, 4} = -2(1\pm \mathrm{i})\)
\(x_{1, 2} = \frac{\sqrt{2}} {2} (1\pm \mathrm{i}),\ x_{3, 4} = -\frac{\sqrt{2}} {2} (1\pm \mathrm{i})\)

9000034704

Level: 
B
Solve the inequality \[ ax - 2 > 0 \] with a real unknown \(x\) and a nonpositive real parameter \(a < 0\).
\(\left (-\infty ; \frac{2} {a}\right )\)
\(\left (-\infty ;-\frac{2} {a}\right )\)
\(\left (\frac{2} {a};\infty \right )\)
\(\left (-\frac{2} {a};\infty \right )\)

9000034306

Level: 
B
Solve the following equation in the set of complex numbers. \[ x^{6} - 64 = 0 \]
\(x_{1, 2} =\pm 2,\ x_{3, 4} = 1\pm \mathrm{i}\sqrt{3},\ x_{5, 6} = -1\pm \mathrm{i}\sqrt{3}\)
\(x_{1, 2} =\pm 2,\ x_{3, 4} = \frac{1} {2}\pm \mathrm{i}\frac{\sqrt{3}} {2} ,\ x_{5, 6} = -\frac{1} {2}\pm \mathrm{i}\frac{\sqrt{3}} {2} \)
\(x_{1, 2} =\pm 4,\ x_{3, 4} = 1\pm \mathrm{i}\sqrt{3},\ x_{5, 6} = -1\pm \mathrm{i}\sqrt{3}\)
\(x_{1, 2} =\pm 8,\ x_{3, 4} = 2\pm 2\mathrm{i}\sqrt{3},\ x_{5, 6} = -2\pm 2\mathrm{i}\sqrt{3}\)

9000034705

Level: 
B
Solve the inequality \[ 2x + b > 0 \] with a real unknown \(x\) and a real parameter \(b\in \mathbb{R}\).
\(\left (-\frac{b} {2};\infty \right )\)
\(\left (\frac{b} {2};\infty \right )\)
\(\left (-\infty ; \frac{b} {2}\right )\)
\(\left (-\infty ;-\frac{b} {2}\right )\)

9000034807

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

9000034905

Level: 
B
The solution set of one of the following quadratic inequalities is the interval \(\left [ -\frac{7} {6}; \frac{3} {4}\right ] \). Determine this inequality.
\(\left (x + \frac{7} {6}\right )\left (x -\frac{3} {4}\right )\leq 0\)
\(\left (x + \frac{7} {6}\right )\left (x -\frac{3} {4}\right )\geq 0\)
\(\left (x -\frac{7} {6}\right )\left (x + \frac{3} {4}\right )\geq 0\)
\(\left (x -\frac{7} {6}\right )\left (x + \frac{3} {4}\right )\leq 0\)