Quadratic equations with complex roots

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 \(x_{1, 2} = 1\pm \frac{\mathrm{i}} {2}\).
\(a = 4\text{, }b = -8\text{, }c = 5\)
\(a = 1\text{, }b = -4\text{, }c = 5\)
\(a = 4\text{, }b = 8\text{, }c = 5\)
\(a = 1\text{, }b = 4\text{, }c = 5\)

1003107501

Level: 
C
Find the complex roots of the following quadratic equation. \[ 2\mathrm{i}\,x^2 - 5\mathrm{i}\,x = 0 \]
\( x_1=0\text{, }\ x_2 = \frac52 \)
\( x_1=0\text{, }\ x_2 = \frac52\mathrm{i} \)
\( x_1=0\text{, }\ x_2 = -\frac52 \)
\( x_1=0\text{, }\ x_2 = -\frac52\mathrm{i} \)

1003107503

Level: 
C
Find the complex roots of the following quadratic equation. \[ (3-\mathrm{i})x^2-(1-2\mathrm{i})x = 0 \]
\( x_1=0\text{, }\ x_2=\frac12-\frac12\mathrm{i} \)
\( x_1=0\text{, }\ x_2=-\frac12+\frac12\mathrm{i} \)
\( x_1=0\text{, }\ x_2=\frac12+\frac12\mathrm{i} \)
\( x_1=0\text{, }\ x_2=-\frac12-\frac12\mathrm{i} \)

1003107504

Level: 
C
Find the complex roots of the following quadratic equation. \[ 16\mathrm{i}x^2- 9\mathrm{i}^3 = 0 \]
\( x_1=\frac34\mathrm{i}\text{, }\ x_2=-\frac34\mathrm{i} \)
\( x_1=\frac34\text{, }\ x_2=-\frac34\)
\( x_1=\frac43\mathrm{i}\text{, }\ x_2=-\frac43\mathrm{i} \)
\( x_1=\frac43\text{, }\ x_2=-\frac43 \)

1003107505

Level: 
C
Find the complex roots of the following quadratic equation. \[ 4\mathrm{i}x^2 + 1 = 0 \]
\( x_1=\frac{\sqrt2}4+\frac{\sqrt2}4\mathrm{i}\text{, }\ x_2=-\frac{\sqrt2}4-\frac{\sqrt2}4\mathrm{i} \)
\( x_1=-\frac{\sqrt2}4+\frac{\sqrt2}4\mathrm{i}\text{, }\ x_2=\frac{\sqrt2}4-\frac{\sqrt2}4\mathrm{i} \)
\( x_1=\frac12+\frac12\mathrm{i}\text{, }\ x_2=-\frac12-\frac12\mathrm{i} \)
\( x_1=-\frac12+\frac12\mathrm{i}\text{, }\ x_2=\frac12-\frac12\mathrm{i} \)