यदि \(\alpha=2+\sqrt{5}\) और \(\beta=2-\sqrt{5}\), तो \(\frac{1}{\alpha}+\frac{1}{\beta}\) क्या है?
If \(\alpha=2+\sqrt{5}\) and \(\beta=2-\sqrt{5}\), what is \(\frac{1}{\alpha}+\frac{1}{\beta}\)?
Explanation opens after your attempt
Correct Answer
A. (-4)
Concept
\(\frac{1}{\alpha}+\frac{1}{\beta}=\frac{\alpha+\beta}{\alpha\beta}=\frac{4}{4-5}=-4\). Finding sum and product first is easier.
Why this answer is correct
The correct answer is A. (-4). \(\frac{1}{\alpha}+\frac{1}{\beta}=\frac{\alpha+\beta}{\alpha\beta}=\frac{4}{4-5}=-4\). Finding sum and product first is easier.
Exam Tip
\(\frac{1}{\alpha}+\frac{1}{\beta}=\frac{\alpha+\beta}{\alpha\beta}=\frac{4}{4-5}=-4\)। पहले योग और गुणनफल निकालना आसान रहता है।
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