Question : If $\operatorname{tan} 15^{\circ}=2-\sqrt{3}$, then the value of $\operatorname{tan} 15^{\circ} \operatorname{cot} 75^{\circ}+\operatorname{tan} 75^{\circ} \operatorname{cot} 15^{\circ}$ is:
Option 1: 6
Option 2: 10
Option 3: 8
Option 4: 14
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Correct Answer: 14
Solution : Given: $\tan 15°= 2 - \sqrt{3}$ and $\cot 15° = \frac{1}{\tan15°}=\frac{1}{(2 - \sqrt{3})} =2+\sqrt{3}$ [on rationalizing] $\tan 15° × \cot 75° + \tan 75° × \cot 15°$ = $\tan 15° × \cot (90° – 15°) + \tan (90° – 15°) × \cot 15°$ = $\tan 15° × \tan 15° + \cot 15° × \cot 15°$ = $\tan^2 15°+\cot^2 15°$ = $(2 - \sqrt{3})^2+(2 + \sqrt{3})^2$ = $7 - 4\sqrt{3} + 7 + 4\sqrt{3}$ = $7 + 7$ = $14$ Hence, the correct answer is 14.
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Question : If $\mathrm{A}=\cot 30^{\circ} \tan 60^{\circ}+\cot 60^{\circ} \tan 30^{\circ}$, then what is the value of A?
Option 1: $\frac{1}{ \sqrt{ 3}}$
Option 2: $\frac{10}{3}$
Option 3: $\frac{10}{ \sqrt{3}}$
Option 4: $\frac{1}{3}$
Question : Find the value of $\cos 0^{\circ}+\cos 30^{\circ}-\tan 45^{\circ}+\operatorname{cosec} 60^{\circ}+\cot 90^{\circ}$.
Option 1: $\frac{7}{6 \sqrt{3}}$
Option 2: $\frac{\sqrt{3}}{6}$
Option 3: $\frac{7}{6}$
Option 4: $\frac{7}{2 \sqrt{3}}$
Question : The value of the expression $\left[\operatorname{cot} 1^{\circ} \cdot \operatorname{cot} 2^{\circ} \cdot \operatorname{cot} 3^{\circ} \cdot \operatorname{cot} 4^{\circ} \cdot \operatorname{cot} 5^{\circ} \ldots . \operatorname{cot} 178^{\circ} \cdot \operatorname{cot} 179^{\circ}\right]$ is:
Option 1: $1235$
Option 2: $\frac{1}{2}$
Option 3: $1$
Option 4: $0$
Question : If $\sqrt{3} \tan ^2 \theta-4 \tan \theta+\sqrt{3}=0$, then what is the value of $\tan ^2 \theta+\cot ^2 \theta$?
Option 1: $\frac{4}{3}$
Option 3: $3$
Option 4: $\frac{6}{5}$
Question : If $\tan(5\theta-10^\circ)=\cot(5\varphi+20^\circ)$, then the value of $(\theta+\varphi)$ is:
Option 1: $16^\circ$
Option 2: $18^\circ$
Option 3: $15^\circ$
Option 4: $20^\circ$
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