Suppose θ is an angle such that sinθ>0 and cosθ<0.
(i) Identify the quadrant in which θ lies.
(ii) Determine the signs of secθ and cscθ separately.
(iii) Show that the product secθcscθ must be negative for every such θ.
(iv) Is it possible for secθcscθ=0 for any real θ? Give reasons for your answer.