Quadratic equations with complex roots

1003107506

Level: 
C
Find the complex roots of the following quadratic equation. \[ 9x^2 + 4\mathrm{i} = 0 \]
\( x_1=-\frac{\sqrt2}3+\frac{\sqrt2}3\mathrm{i}\text{, }\ x_2=\frac{\sqrt2}3-\frac{\sqrt2}3\mathrm{i} \)
\( x_1=\frac23\mathrm{i}\text{, }\ x_2=-\frac23\mathrm{i} \)
\( x_1=\frac{\sqrt2}3+\frac{\sqrt2}3\mathrm{i}\text{, }\ x_2=-\frac{\sqrt2}3-\frac{\sqrt2}3\mathrm{i} \)
\( x_1=\frac23\text{, }\ x_2=-\frac23 \)

1003107507

Level: 
C
Find the solution set of the following quadratic equation in the complex plane. \[ x^2 +3\mathrm{i}x + 10 = 0 \]
\( \{-5\mathrm{i}; 2\mathrm{i}\} \)
\( \{-2\mathrm{i}; 5\mathrm{i}\} \)
\( \{2-5\mathrm{i}; 5-2\mathrm{i}\} \)
\( \{-2+5\mathrm{i}; -5+2\mathrm{i}\} \)
\( \emptyset \)

1003107509

Level: 
C
Find the solution set of the following quadratic equation in the complex plane. \[ (3-2\mathrm{i})x^2-(2-4\mathrm{i})x + 2 = 0 \]
\( \left\{ 1-\mathrm{i}; \frac1{13}+\frac5{13}\mathrm{i} \right\} \)
\( \left\{ -1+\mathrm{i}; -\frac1{13}-\frac5{13}\mathrm{i} \right\} \)
\( \emptyset \)
\( \left\{ -1+\mathrm{i}; \frac1{13}+\frac5{13}\mathrm{i} \right\} \)
\( \left\{ 1-\mathrm{i}; -\frac1{13}-\frac5{13}\mathrm{i} \right\} \)

1003107510

Level: 
C
Find the solution set of the following quadratic equation in the complex plane. \[ x+\frac{\mathrm{i}}2=\frac1x+\frac2{\mathrm{i}} \]
\( \left\{-\frac12\mathrm{i};-2\mathrm{i} \right\} \)
\( \left\{\frac12\mathrm{i};2\mathrm{i} \right\} \)
\( \left\{\frac12\mathrm{i};-2\mathrm{i} \right\} \)
\( \left\{-\frac12\mathrm{i};2\mathrm{i} \right\} \)
\( \emptyset \)

1003107511

Level: 
C
Find the solution set of the following quadratic equation in the complex plane. \[ 2x^2-x=3\mathrm{i}x+2 \]
\( \left\{-\frac12+\frac12\mathrm{i}; 1+\mathrm{i} \right\} \)
\( \left\{-\frac12+\mathrm{i}; 1+\frac12\mathrm{i} \right\} \)
\( \left\{\frac12-\frac12\mathrm{i}; -1-\mathrm{i} \right\} \)
\( \left\{\frac12-\mathrm{i}; -1-\frac12\mathrm{i} \right\} \)
\( \left\{-\frac12-\frac12\mathrm{i}; 1-\mathrm{i} \right\} \)
\( \left\{\frac12+\mathrm{i}; -1+\frac12\mathrm{i} \right\} \)

1003109401

Level: 
C
Which of the given quadratic equations has the roots \( x_1 = 2 + \mathrm{i} \) and \( x_2 = 1 - 3\,\mathrm{i} \)?
\( x^2 - (3 - 2\,\mathrm{i})x + 5 - 5\,\mathrm{i} = 0 \)
\(x^2 + (3 - 2\,\mathrm{i})x + 5 - 5\,\mathrm{i} = 0 \)
\( x^2 - (3 + 2\,\mathrm{i})x + 5 - 5\,\mathrm{i} = 0 \)
\( x^2 + (3 + 2\,\mathrm{i})x + 5 - 5\,\mathrm{i} = 0 \)

1003109402

Level: 
C
Which of the given quadratic equations has the roots \( x_1 = 1 +\mathrm{i} \) and \( x_2 = (1 +\mathrm{i})^2 \)?
\( x^2 - (1 + 3\,\mathrm{i})x - 2 + 2\,\mathrm{i} = 0 \)
\( x^2 - (1 + 3\,\mathrm{i})x - 2 - 2\,\mathrm{i} = 0 \)
\( x^2 - (1 + 3\,\mathrm{i})x + 2 + 2\,\mathrm{i} = 0 \)
\( x^2 - (1 + 3\,\mathrm{i})x + 2 - 2\,\mathrm{i} = 0 \)

1003109403

Level: 
C
One of the following equations has the solutions \( x_1=\frac12-\mathrm{i} \) and \( x_2=-\frac12+2\,\mathrm{i} \). Find this equation.
\( 4x^2-4\,\mathrm{i}\,x+7+6\,\mathrm{i}=0 \)
\( 4x^2-4\,\mathrm{i}\,x-9+3\,\mathrm{i}=0 \)
\( 4x^2+4\,\mathrm{i}\,x+7+6\,\mathrm{i}\,=0 \)
\( 4x^2+4\,\mathrm{i}\,x-9+3\,\mathrm{i}=0 \)

1003109404

Level: 
C
One of the roots of the quadratic equation \( x^2 + px + 1 - 3\,\mathrm{i} = 0 \) with a complex parameter \( p \) is \( x_1 = -\mathrm{i} \). Choose the equivalent form of the given equation.
\( (x + \mathrm{i})(x -3 - \mathrm{i}) = 0 \)
\( (x + \mathrm{i})(x - 3 +\mathrm{i}) = 0 \)
\( (x -\mathrm{i})(x- 3-\mathrm{i}) = 0 \)
\( (x +\mathrm{i})(x + 3 + \mathrm{i}) = 0 \)
\( (x -\mathrm{i})(x- 3 + \mathrm{i}) = 0 \)
\( (x -\mathrm{i})(x + 3 +\mathrm{i}) = 0 \)