Answer
$\sin y$
Work Step by Step
Given expression is-
$ \frac{1 + \sin y}{1 + \csc y} $
= $ \frac{1 + \sin y}{1 + \frac{1}{\sin y}} $
= $ \frac{1 + \sin y}{\frac{\sin y + 1}{\sin y}} $
= $ (1 + \sin y) . \frac{\sin y}{(\sin y + 1)} $
= $\sin y$
