Answer: C
\(3x+ \cfrac{3}{x}=\csc\alpha+\cot\alpha \)
Or, \(3\left(x+\cfrac{1}{x}\right)=\csc\alpha+\cot\alpha\)
Again, \(3x-\cfrac{3}{x}=\csc\alpha-\cot\alpha \)
Or, \(3(x-\cfrac{1}{x})=\csc\alpha-\cot\alpha\)
∴ \(3(x+\cfrac{1}{x})\times 3(x-\cfrac{1}{x})\)
\(=(\csc\alpha+\cot\alpha )(\csc\alpha-\cot\alpha)\)
Or, \(3\times 3\left(x^2-\cfrac{1}{x^2} \right)=\csc^2 \alpha-\cot^2\alpha\)
Or, \(3\times 3\left(x^2-\cfrac{1}{x^2}\right)=1\)
Or, \(3\left(x^2-\cfrac{1}{x^2}\right)=\cfrac{1}{3}\)
(Answer)
\(3x+ \cfrac{3}{x}=\csc\alpha+\cot\alpha \)
Or, \(3\left(x+\cfrac{1}{x}\right)=\csc\alpha+\cot\alpha\)
Again, \(3x-\cfrac{3}{x}=\csc\alpha-\cot\alpha \)
Or, \(3(x-\cfrac{1}{x})=\csc\alpha-\cot\alpha\)
∴ \(3(x+\cfrac{1}{x})\times 3(x-\cfrac{1}{x})\)
\(=(\csc\alpha+\cot\alpha )(\csc\alpha-\cot\alpha)\)
Or, \(3\times 3\left(x^2-\cfrac{1}{x^2} \right)=\csc^2 \alpha-\cot^2\alpha\)
Or, \(3\times 3\left(x^2-\cfrac{1}{x^2}\right)=1\)
Or, \(3\left(x^2-\cfrac{1}{x^2}\right)=\cfrac{1}{3}\)
(Answer)