A

2000001904

Level: 
A
The picture shows the graphical solution of an equation. Which equation is it?
\[ \sin{x} = -\frac{1}{2} \] \[ x \in [ 0;2\pi ]\]
\[ \sin{x} = -\frac{\sqrt{3}}{2} \] \[ x \in [ 0;2\pi ]\]
\[ \cos{x} = -\frac{1}{2} \] \[ x \in [ 0;2\pi ]\]
\[ \cos{x} = -\frac{\sqrt{3}}{2} \] \[ x \in [ 0;2\pi ]\]

2000001903

Level: 
A
The picture shows the graphical solution of an equation. Which equation is it?
\[ \sin{x} = -\frac{\sqrt{3}}{2} \] \[ x \in [ 0;2\pi ]\]
\[ \sin{x} = -\frac{1}{2} \] \[ x \in [ 0;2\pi ]\]
\[ \cos{x} = -\frac{\sqrt{3}}{2} \] \[ x \in [ 0;2\pi ]\]
\[ \cos{x} = -\frac{1}{2} \] \[ x \in [ 0;2\pi ]\]

2000001902

Level: 
A
The picture shows the graphical solution of an equation. Which equation is it?
\[ \cos{x} = -\frac{\sqrt{3}}{2}\] \[ x \in [ 0; 2\pi ] \]
\[ \sin{x} = -\frac{\sqrt{3}}{2}\] \[ x \in [ 0; 2\pi ] \]
\[ \sin{x} = -\frac{1}{2}\] \[ x \in [ 0; 2\pi ] \]
\[ \cos{x} = -\frac{1}{2}\] \[ x \in [ 0; 2\pi ] \]

2000001901

Level: 
A
The picture shows the graphical solution of an equation. Which equation is it?
\[ \cos{x} = -\frac{1}{2} \] \[ x \in [ 0;2\pi ]\]
\[ \sin{x} = -\frac{1}{2} \] \[ x \in [ 0;2\pi ]\]
\[ \cos{x} = -\frac{\sqrt{3}}{2} \] \[ x \in [ 0;2\pi ]\]
\[ \sin{x} = -\frac{\sqrt{3}}{2} \] \[ x \in [ 0;2\pi ]\]

2000001512

Level: 
A
Let \( x_1=2-\frac{\sqrt{5}}{2}i\) be one of the roots of a quadratic equation with real coefficients. Find the other root \(x_2\) of this equation.
\( x_2 =2+\frac{\sqrt{5}}{2}i\)
\( x_2 =-2-\frac{\sqrt{5}}{2}i\)
\( x_2 =-2+\frac{\sqrt{5}}{2}i\)
\( x_2 = \frac{1}{2-\frac{\sqrt{5}}{2}i}\)

2000001506

Level: 
A
Factorize the equation \(4x^2+25=0\) in the set of complex numbers.
\( 4\left( x-\frac{5}{2}i\right)\left( x+\frac{5}{2}i\right)=0\)
\(( 2x+5)( 2x+5)=0\)
\( 4\left( x+\frac{5}{2}i\right)\left( x+\frac{5}{2}i\right)=0\)
\( 4\left( x-\frac{5}{2}i\right)\left( x-\frac{5}{2}i\right)=0\)