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If sinθ = -1/2 and θ is in Quadrant III, then tanθ = _____.

User Yeputons
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2 Answers

3 votes
tan tetha at quadrant III would be
( √(3) )/(3)
User Robin Hartmann
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5 votes

Answer:
\tan \theta=(1)/(\sqrt3).

Step-by-step explanation: Given that


\sin\theta=-(1)/(2) and
\theta lies in Quadrant III.

We are to find the value of
\tan \theta.

We will be using the following trigonometric identities:


(i)~sin^2\theta+\cos^2\theta=1,\\\\(ii)~(\sin\theta)/(cos(\theta))=\tan \theta.

We have


\tan\theta\\\\\\=(\sin\theta)/(\cos\theta)\\\\\\=(\sin\theta)/(\pm√(1-\sin^2\theta))\\\\\\=\pm\frac{-(1)/(2)}{\sqrt{1-\left((1)/(2)\right)^2}}\\\\\\=\pm\frac{(1)/(2)}{\sqrt{1-(1)/(4)}}\\\\\\=\pm((1)/(2))/((\sqrt3)/(2))\\\\\\=\pm(1)/(\sqrt3).

Since
\theta lies in Quadrant III, so tangent will be positive.

Thus,


\tan \theta=(1)/(\sqrt3).

User Oyeraghib
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