That would be
cos x
sin x + cos x * --------
sin x
sin x
Mult sin x by ----------
sin x
to obtain
(sin x)^2
------------
sin x
and then add
(cos x)^2
-------------
sin x
with the outcome being
(sin x)^2 + (cos x)^2 1
--------------------------- = --------- = cos x (answer)
sin x sin x