COMEDK · Maths · 2. Quadratic Equation
The real root of the equation \(x^{3}-6 x+9=0\) is
- A \(-6\)
- B \(-9\)
- C 6
- D \(-3\)
Answer & Solution
Correct Answer
(D) \(-3\)
Step-by-step Solution
Detailed explanation
We have, \[ \begin{gathered} x^{3}-6 x+9=0 \\ \Rightarrow \quad(x+3)\left(x^{2}-3 x+3\right)=0 \\ \Rightarrow \quad x+3=0 \quad\left[\because x^{2}-3 x+3 \neq 0, x \in R\right] \\ \Rightarrow \quad x=-3 \end{gathered} \]
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