JEE Mains · Maths · STD 11 - 4.2 Quadratic equations and inequations
The product of the roots of the equation \(9 x^{2}-18|x|+5=0,\) is
- A \(\frac{25}{9}\)
- B \(\frac{25}{81}\)
- C \(\frac{5}{27}\)
- D \(\frac{5}{9}\)
Answer & Solution
Correct Answer
(B) \(\frac{25}{81}\)
Step-by-step Solution
Detailed explanation
\(9 x^{2}-18|x|+5=0\) \(9|x|^{2}-15|x|-3|x|+5=0\left(\because x^{2}=|x|^{2}\right)\) \(3|x|(3|x|-5)-(3|x|-5)=0\) \(|x|=\frac{1}{3}, \frac{5}{3}\) \(x=\pm \frac{1}{3}, \pm \frac{5}{3}\) Product of roots \(=\frac{25}{81}\)
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