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Tg105°-cotg105° = ?
Please help fast!!! Please

User CodaFi
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1 Answer

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Using only the trig ratios of 45 and 60 degrees, we use angle-sum to compute
\tan 105^\circ=\tan(60^\circ+45^\circ)=(\tan 60^\circ+\tan 45^\circ)/(1-\tan 60^\circ\tan 45^\circ)=(√(3)+1)/(1-√(3))=-2-√(3), so
\cot 105^\circ=(1)/(\tan 105^\circ)=-2+√(3) and
\tan 105^\circ-\cot105^\circ=\boxed{-2√(3)}.

User Gatlin
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