Quadratic Equations with Complex Roots

2000001505

Level: 
B
Which of the numbers below does not satisfy the equation \(2x^2=-16\)?
\( \sqrt{8}(\cos{\pi} +i\sin{\pi})\)
\( 2\sqrt{2}(\cos{\frac{\pi}{2}} +i\sin{\frac{\pi}{2}})\)
\( 2\sqrt{2}\left(\cos{\left(-\frac{\pi}{2}\right)} +i\sin{\left(-\frac{\pi}{2}\right)}\right)\)
\( 2\sqrt{2}i\)

1003107511

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

1003107510

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

1003107509

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