9000064501
Level:
B
Find the quadratic equation with the solution
\(x_{1, 2} =\pm 2\mathrm{i}\).
\(x^{2} + 4 = 0\)
\(x^{2} - 4\mathrm{i} = 0\)
\(x^{2} - 4 = 0\)
\(x^{2} + 4\mathrm{i} = 0\)
Quadratic Equations with Complex Roots
9000064502
Level:
B
Find the quadratic equation with the solution
\(x_{1, 2} = 2\pm \mathrm{i}\sqrt{2}\).
\(x^{2} - 4x + 6 = 0\)
\(3x^{2} + 4x + 2 = 0\)
\(3x^{2} - 4x + 2 = 0\)
\(x^{2} + 4x + 6 = 0\)
9000064503
Level:
B
Find the values of the real coefficients
\(a\),
\(b\) and
\(c\) such
that the quadratic equation
\[
ax^{2} + bx + c = 0
\]
has solution \(x_{1, 2} =\pm \mathrm{i}\frac{\sqrt{5}}
{3} \).
\(a = 9\text{, }b = 0\text{, }c = 5\)
\(a = 5\text{, }b = 0\text{, }c = 9\)
\(a = 9\text{, }b = 0\text{, }c = -5\)
\(a = 5\text{, }b = 0\text{, }c = -9\)
9000064504
Level:
B
Find the values of the real coefficients
\(a\),
\(b\) and
\(c\) such
that the quadratic equation
\[
ax^{2} + bx + c = 0
\]
has solutions \(x_{1, 2} = 1\pm \frac{\mathrm{i}}
{2}\).
\(a = 4\text{, }b = -8\text{, }c = 5\)
\(a = 1\text{, }b = -4\text{, }c = 5\)
\(a = 4\text{, }b = 8\text{, }c = 5\)
\(a = 1\text{, }b = 4\text{, }c = 5\)
9000039107
Level:
A
Find the sum of the reciprocal values of the solutions of
\(5x^{2} - 2x + 1 = 0\).
\(2\)
\(\frac{2}
{5}\)
\(\frac{2}
{5} + \frac{4}
{5}\mathrm{i}\)
\(-\frac{2}
{5}\)
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
9000039105
Level:
B
Find the quadratic equation with real coefficients such that one of the solutions is the complex
number \(x_{1} = 1 + 2\mathrm{i}\).
\(x^{2} - 2x + 5 = 0\)
\(x^{2} - 2x + 3 = 0\)
\(x^{2} + 2x + 5 = 0\)
\(x^{2} + 2x - 3 = 0\)
9000035603
Level:
A
Find the solution set of the following equation.
\[
4x^{2} + 9 = 0
\]
\(\left \{-\frac{3}
{2}\mathrm{i}; \frac{3}
{2}\mathrm{i}\right \}\)
\(\left \{-\frac{2}
{3}\mathrm{i}; \frac{2}
{3}\mathrm{i}\right \}\)
\(\left \{-\frac{9}
{4}\mathrm{i}; \frac{9}
{4}\mathrm{i}\right \}\)
\(\left \{-\frac{3}
{2}; \frac{3}
{2}\right \}\)
9000035607
Level:
C
Identify the quadratic equation with solutions
\(x_{1} = 2\mathrm{i}\),
\(x_{2} = -\mathrm{i}\).
\(x^{2} -\mathrm{i}x + 2 = 0\)
\(x^{2} + \mathrm{i}x + 2 = 0\)
\(x^{2} + \mathrm{i}x - 2 = 0\)
\(x^{2} -\mathrm{i}x - 2 = 0\)
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 \(q\).
\(x_{2} = -1,\ q = -1 - 2\mathrm{i}\)
\(x_{2} = -1 - 4\mathrm{i},\ q = 9 - 6\mathrm{i}\)
\(x_{2} = 1 - 4\mathrm{i},\ q = 7 - 4\mathrm{i}\)
\(x_{2} = 1,\ q = -1 - 2\mathrm{i}\)
\(x_{2} = -1,\ q = 1 + 2\mathrm{i}\)