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方程 有一个根 ,其中 和 是实常数。
求 和 的值以及该方程的所有其他根。
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完整解法
3
1. Identify the complex conjugate root using the property of real coefficients.
Since the coefficients and are real constants, the complex conjugate of the given root must also be a root of the equation.
Therefore, is another root.
2. Form the quadratic factor corresponding to the two complex roots.
The quadratic factor having these roots is:
3. Set up an identity to find the remaining linear factor.
Since is a cubic equation with leading coefficient , it can be expressed as the product of the quadratic factor and a linear factor :
Expanding the right side gives:
Comparing the coefficient of :
4. Compare the remaining coefficients to solve for $p$ and $q$.
Substitute into the expanded expression and compare coefficients.
Comparing the coefficient of :
Comparing the constant term:
5. Solve the linear factor to find the third root.
The linear factor is . Setting this to zero gives the final root:
The other roots of the equation are therefore and .
Other roots: and
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