Problem

Problem

Let θ,ϕ∈[0,2π]\theta, \phi \in [0, 2\pi] be such that 2cos⁡θ(1−sin⁡ϕ)=sin⁡2θ(tan⁡θ2+cot⁡θ2)cos⁡ϕ−1,2 \cos \theta (1 - \sin \phi) = \sin^2 \theta \left( \tan \frac{\theta}{2} + \cot \frac{\theta}{2} \right) \cos \phi - 1, tan⁡(2π−θ)>0\tan(2\pi - \theta) > 0, and −1<sin⁡θ<−32-1 < \sin \theta < -\frac{\sqrt{3}}{2}. Then, ϕ\phi cannot satisfy a. 0<ϕ<π20 < \phi < \frac{\pi}{2} b. π2<ϕ<4π3\frac{\pi}{2} < \phi < \frac{4\pi}{3} c. 4π3<ϕ<3π2\frac{4\pi}{3} < \phi < \frac{3\pi}{2} d. 3π2<ϕ<2π\frac{3\pi}{2} < \phi < 2\pi

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