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If \(\cot(A - B) = \sqrt{3}\), then find the value of \(\frac{\cot B - \cot A}{\cot A\cot B + 1} + \frac{\tan A - \tan B}{1 + \tan A\tan B}\).

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RRB Technician 2026 Grade 3 Question Paper (7-Oct-2026) (Shift 3)
The correct answer is

\(\frac{2\sqrt{3}}{3}\)

Recall \(\cot(A - B) = \frac{\cot A\cot B + 1}{\cot B - \cot A}\), so the first term \(\frac{\cot B - \cot A}{\cot A\cot B + 1} = \frac{1}{\cot(A - B)} = \tan(A - B)\)

Also \(\frac{\tan A - \tan B}{1 + \tan A\tan B} = \tan(A - B)\)

Given \(\cot(A - B) = \sqrt{3}\), so \(\tan(A - B) = \frac{1}{\sqrt{3}}\)

Sum = \(\frac{1}{\sqrt{3}} + \frac{1}{\sqrt{3}} = \frac{2}{\sqrt{3}} = \frac{2\sqrt{3}}{3}\)

Hence, the answer is \(\frac{2\sqrt{3}}{3}\).

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