Solution of Quadratic and Higher Degree Equations
Complex Numbers and Quadratic Equation

118191 If the maximum value of \(2 x-7-\mathrm{ax}^2\) cannot exceed 20, then the minimum value of a is

1 27
2 \(\frac{1}{13}\)
3 13
4 \(\frac{1}{27}\)
Complex Numbers and Quadratic Equation

118192 Let the transformed equation of \(2 x^4-8 x^3+3 x^2-1=0\) so that the term containing the cubic power of \(x\) is absent be \(\mathbf{2} \mathbf{x}^4+b x^2+\mathbf{c x}+\mathbf{d}=\mathbf{0}\). Then, \(\mathrm{b}=\)

1 -18
2 -15
3 -9
4 -16
Complex Numbers and Quadratic Equation

118193 If \(\frac{5}{2}\) is the sum of two roots of the equation \(6 x^6-25 x^5+31 x^4-31 x^2+25 x-6=0\) th en the sum of all non-real roots of the equation is

1 does not exist
2 0
3 \(\frac{5}{3}\)
4 \(\frac{2}{5}\)
Complex Numbers and Quadratic Equation

118194 Let
\(A_r=\left(x+\frac{1}{x}\right)^3 \cdot\left(x^2+\frac{1}{x^2}\right)^3 \cdot\left(x^3+\frac{1}{x^3}\right)^3 \ldots\)
\(\left(x^r+\frac{1}{x^r}\right)^3 \cdot\) If \(x^2+x+1=0\), then
\(\frac{1}{\mathrm{~A}_3}+\frac{1}{\mathrm{~A}_6}+\frac{1}{\mathrm{~A}_9}+\frac{1}{\mathrm{~A}_{12}}+\ldots \infty=\)

1 \(\frac{1}{6}\)
2 \(\frac{2}{5}\)
3 1
4 \(\frac{1}{7}\)
Complex Numbers and Quadratic Equation

118195 If \(\alpha\) is a root of multiplicity 3 of the equation \(x^5-8 x^4+25 x^3-38 x^2+28 x-8=0\), then \(\alpha^2-5 \alpha+6=\)

1 0
2 1
3 2
4 3
Complex Numbers and Quadratic Equation

118191 If the maximum value of \(2 x-7-\mathrm{ax}^2\) cannot exceed 20, then the minimum value of a is

1 27
2 \(\frac{1}{13}\)
3 13
4 \(\frac{1}{27}\)
Complex Numbers and Quadratic Equation

118192 Let the transformed equation of \(2 x^4-8 x^3+3 x^2-1=0\) so that the term containing the cubic power of \(x\) is absent be \(\mathbf{2} \mathbf{x}^4+b x^2+\mathbf{c x}+\mathbf{d}=\mathbf{0}\). Then, \(\mathrm{b}=\)

1 -18
2 -15
3 -9
4 -16
Complex Numbers and Quadratic Equation

118193 If \(\frac{5}{2}\) is the sum of two roots of the equation \(6 x^6-25 x^5+31 x^4-31 x^2+25 x-6=0\) th en the sum of all non-real roots of the equation is

1 does not exist
2 0
3 \(\frac{5}{3}\)
4 \(\frac{2}{5}\)
Complex Numbers and Quadratic Equation

118194 Let
\(A_r=\left(x+\frac{1}{x}\right)^3 \cdot\left(x^2+\frac{1}{x^2}\right)^3 \cdot\left(x^3+\frac{1}{x^3}\right)^3 \ldots\)
\(\left(x^r+\frac{1}{x^r}\right)^3 \cdot\) If \(x^2+x+1=0\), then
\(\frac{1}{\mathrm{~A}_3}+\frac{1}{\mathrm{~A}_6}+\frac{1}{\mathrm{~A}_9}+\frac{1}{\mathrm{~A}_{12}}+\ldots \infty=\)

1 \(\frac{1}{6}\)
2 \(\frac{2}{5}\)
3 1
4 \(\frac{1}{7}\)
Complex Numbers and Quadratic Equation

118195 If \(\alpha\) is a root of multiplicity 3 of the equation \(x^5-8 x^4+25 x^3-38 x^2+28 x-8=0\), then \(\alpha^2-5 \alpha+6=\)

1 0
2 1
3 2
4 3
Complex Numbers and Quadratic Equation

118191 If the maximum value of \(2 x-7-\mathrm{ax}^2\) cannot exceed 20, then the minimum value of a is

1 27
2 \(\frac{1}{13}\)
3 13
4 \(\frac{1}{27}\)
Complex Numbers and Quadratic Equation

118192 Let the transformed equation of \(2 x^4-8 x^3+3 x^2-1=0\) so that the term containing the cubic power of \(x\) is absent be \(\mathbf{2} \mathbf{x}^4+b x^2+\mathbf{c x}+\mathbf{d}=\mathbf{0}\). Then, \(\mathrm{b}=\)

1 -18
2 -15
3 -9
4 -16
Complex Numbers and Quadratic Equation

118193 If \(\frac{5}{2}\) is the sum of two roots of the equation \(6 x^6-25 x^5+31 x^4-31 x^2+25 x-6=0\) th en the sum of all non-real roots of the equation is

1 does not exist
2 0
3 \(\frac{5}{3}\)
4 \(\frac{2}{5}\)
Complex Numbers and Quadratic Equation

118194 Let
\(A_r=\left(x+\frac{1}{x}\right)^3 \cdot\left(x^2+\frac{1}{x^2}\right)^3 \cdot\left(x^3+\frac{1}{x^3}\right)^3 \ldots\)
\(\left(x^r+\frac{1}{x^r}\right)^3 \cdot\) If \(x^2+x+1=0\), then
\(\frac{1}{\mathrm{~A}_3}+\frac{1}{\mathrm{~A}_6}+\frac{1}{\mathrm{~A}_9}+\frac{1}{\mathrm{~A}_{12}}+\ldots \infty=\)

1 \(\frac{1}{6}\)
2 \(\frac{2}{5}\)
3 1
4 \(\frac{1}{7}\)
Complex Numbers and Quadratic Equation

118195 If \(\alpha\) is a root of multiplicity 3 of the equation \(x^5-8 x^4+25 x^3-38 x^2+28 x-8=0\), then \(\alpha^2-5 \alpha+6=\)

1 0
2 1
3 2
4 3
Complex Numbers and Quadratic Equation

118191 If the maximum value of \(2 x-7-\mathrm{ax}^2\) cannot exceed 20, then the minimum value of a is

1 27
2 \(\frac{1}{13}\)
3 13
4 \(\frac{1}{27}\)
Complex Numbers and Quadratic Equation

118192 Let the transformed equation of \(2 x^4-8 x^3+3 x^2-1=0\) so that the term containing the cubic power of \(x\) is absent be \(\mathbf{2} \mathbf{x}^4+b x^2+\mathbf{c x}+\mathbf{d}=\mathbf{0}\). Then, \(\mathrm{b}=\)

1 -18
2 -15
3 -9
4 -16
Complex Numbers and Quadratic Equation

118193 If \(\frac{5}{2}\) is the sum of two roots of the equation \(6 x^6-25 x^5+31 x^4-31 x^2+25 x-6=0\) th en the sum of all non-real roots of the equation is

1 does not exist
2 0
3 \(\frac{5}{3}\)
4 \(\frac{2}{5}\)
Complex Numbers and Quadratic Equation

118194 Let
\(A_r=\left(x+\frac{1}{x}\right)^3 \cdot\left(x^2+\frac{1}{x^2}\right)^3 \cdot\left(x^3+\frac{1}{x^3}\right)^3 \ldots\)
\(\left(x^r+\frac{1}{x^r}\right)^3 \cdot\) If \(x^2+x+1=0\), then
\(\frac{1}{\mathrm{~A}_3}+\frac{1}{\mathrm{~A}_6}+\frac{1}{\mathrm{~A}_9}+\frac{1}{\mathrm{~A}_{12}}+\ldots \infty=\)

1 \(\frac{1}{6}\)
2 \(\frac{2}{5}\)
3 1
4 \(\frac{1}{7}\)
Complex Numbers and Quadratic Equation

118195 If \(\alpha\) is a root of multiplicity 3 of the equation \(x^5-8 x^4+25 x^3-38 x^2+28 x-8=0\), then \(\alpha^2-5 \alpha+6=\)

1 0
2 1
3 2
4 3
Complex Numbers and Quadratic Equation

118191 If the maximum value of \(2 x-7-\mathrm{ax}^2\) cannot exceed 20, then the minimum value of a is

1 27
2 \(\frac{1}{13}\)
3 13
4 \(\frac{1}{27}\)
Complex Numbers and Quadratic Equation

118192 Let the transformed equation of \(2 x^4-8 x^3+3 x^2-1=0\) so that the term containing the cubic power of \(x\) is absent be \(\mathbf{2} \mathbf{x}^4+b x^2+\mathbf{c x}+\mathbf{d}=\mathbf{0}\). Then, \(\mathrm{b}=\)

1 -18
2 -15
3 -9
4 -16
Complex Numbers and Quadratic Equation

118193 If \(\frac{5}{2}\) is the sum of two roots of the equation \(6 x^6-25 x^5+31 x^4-31 x^2+25 x-6=0\) th en the sum of all non-real roots of the equation is

1 does not exist
2 0
3 \(\frac{5}{3}\)
4 \(\frac{2}{5}\)
Complex Numbers and Quadratic Equation

118194 Let
\(A_r=\left(x+\frac{1}{x}\right)^3 \cdot\left(x^2+\frac{1}{x^2}\right)^3 \cdot\left(x^3+\frac{1}{x^3}\right)^3 \ldots\)
\(\left(x^r+\frac{1}{x^r}\right)^3 \cdot\) If \(x^2+x+1=0\), then
\(\frac{1}{\mathrm{~A}_3}+\frac{1}{\mathrm{~A}_6}+\frac{1}{\mathrm{~A}_9}+\frac{1}{\mathrm{~A}_{12}}+\ldots \infty=\)

1 \(\frac{1}{6}\)
2 \(\frac{2}{5}\)
3 1
4 \(\frac{1}{7}\)
Complex Numbers and Quadratic Equation

118195 If \(\alpha\) is a root of multiplicity 3 of the equation \(x^5-8 x^4+25 x^3-38 x^2+28 x-8=0\), then \(\alpha^2-5 \alpha+6=\)

1 0
2 1
3 2
4 3