Quadratic Equations with Complex Roots

9000064505

Level: 
A
Find the factorization of the following quadratic polynomial in the set of polynomial with complex valued coefficients. \[ 2x^{2} + 32 \]
\(2(x + 4\mathrm{i})(x - 4\mathrm{i})\)
\(2(x - 4\mathrm{i})^{2}\)
\((x + 4\mathrm{i})(x - 4\mathrm{i})\)
\(2(x + 4\mathrm{i})^{2}\)

9000064508

Level: 
A
Solve the following quadratic equation in the complex plane. \[ 2x^{2} + x + 1 = 0 \]
\(x_{1, 2} = \frac{-1\pm \mathrm{i}\sqrt{7}} {4} \)
\(x_{1, 2} = \frac{-1\pm \mathrm{i}\sqrt{7}} {2} \)
\(x_{1, 2} = \frac{1\pm \mathrm{i}\sqrt{7}} {4} \)
\(x_{1, 2} = \frac{1\pm \mathrm{i}\sqrt{7}} {2} \)

9000064506

Level: 
A
Find the factorization of the following quadratic polynomial in the set of polynomial with complex valued coefficients. \[ 2x^{2} + 4x + 5 \]
\(2\! \left (x + 1 + \frac{\sqrt{6}} {2} \mathrm{i}\right )\! \! \left (x + 1 -\frac{\sqrt{6}} {2} \mathrm{i}\right )\)
\(2\! \left (x - 1 + \frac{\sqrt{6}} {2} \mathrm{i}\right )\! \! \left (x - 1 -\frac{\sqrt{6}} {2} \mathrm{i}\right )\)
\(\left (x + 1 -\frac{\sqrt{6}} {2} \mathrm{i}\right )\! \! \left (x + 1 + \frac{\sqrt{6}} {2} \mathrm{i}\right )\)
\(\left (x - 1 -\frac{\sqrt{6}} {2} \mathrm{i}\right )\! \! \left (x - 1 + \frac{\sqrt{6}} {2} \mathrm{i}\right )\)

9000039106

Level: 
B
Find the value of the parameter \(a\) which guarantees that the quadratic equation \[ x^{2} + 2ax + a = 0 \] has a pair of complex conjugate solutions with a nonzero imaginary part.
\(a\in (0;1)\)
\(a\in [ 0;1] \)
\(a\in (-\infty ;0)\cup (1;\infty )\)
Such an \(a\) does not exist

9000035603

Level: 
A
Find the solution set of the following equation. \[ 4x^{2} + 9 = 0 \]
\(\left \{-\frac{3} {2}\mathrm{i}; \frac{3} {2}\mathrm{i}\right \}\)
\(\left \{-\frac{2} {3}\mathrm{i}; \frac{2} {3}\mathrm{i}\right \}\)
\(\left \{-\frac{9} {4}\mathrm{i}; \frac{9} {4}\mathrm{i}\right \}\)
\(\left \{-\frac{3} {2}; \frac{3} {2}\right \}\)

9000035608

Level: 
C
The equation \[ x^{2} - 2\mathrm{i}x + q = 0 \] with a parameter \(q\in \mathbb{C}\) has a solution \(x_{1} = 1 + 2\mathrm{i}\). Find the second solution \(x_{2}\) and the parameter \(q\).
\(x_{2} = -1,\ q = -1 - 2\mathrm{i}\)
\(x_{2} = -1 - 4\mathrm{i},\ q = 9 - 6\mathrm{i}\)
\(x_{2} = 1 - 4\mathrm{i},\ q = 7 - 4\mathrm{i}\)
\(x_{2} = 1,\ q = -1 - 2\mathrm{i}\)
\(x_{2} = -1,\ q = 1 + 2\mathrm{i}\)