Let be an angle such that and

MATHEMATICS · Multi-part · CBSE · Mathematics · Trigonometric Functions · Trigonometric Functions

Problem

Let θ\theta be an angle such that π2<θ<π\dfrac{\pi}{2}<\theta<\pi and cos⁡θ=−45\cos \theta=-\dfrac{4}{5}. Answer the following parts. (i) Find sin⁡θ\sin \theta and justify the sign of the result. (ii) Determine tan⁡θ\tan \theta in simplest form. (iii) Using your results, compute tan⁡2θ\tan 2\theta and state clearly whether it is positive or negative.

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