Question

How to evaluate this? ( Continuity and Differentiation )

Answer 1

First I would say to split this into tan(y)/sin^(3)(y) - sin(y)/sin^(3)(y). Then put the tan(y) in terms of sine and cosine and simplify from there. Once you've done that, consider when 1/sin(y) and 1/cos(y) are discontinuous.

Answer 2

I’m not sure what that the question is clear from just the context you’ve provided. Is there a particular value of y you’re being told to evaluate this expression at?