Prove that
sinθcosθ+cosθsinθ≡2cosec2θ\displaystyle \frac{\sin\theta}{\cos\theta} + \frac{\cos\theta}{\sin\theta} \equiv 2\operatorname{cosec}2\thetacosθsinθ+sinθcosθ≡2cosec2θ
Hence solve, for 0°≤θ<360°0° \leq \theta < 360°0°≤θ<360°, the equation
sinθcosθ+cosθsinθ=5\displaystyle \frac{\sin\theta}{\cos\theta} + \frac{\cos\theta}{\sin\theta} = 5cosθsinθ+sinθcosθ=5
Give your answers to one decimal place.