simplify sin(360-x)*tan(-x)/cos(180+x).(sin^2A+cos^2A)

Answer 1

since
sin(360-x) = -sinx
tan(-x) = -tanx
cos(180+x) = -cosx
(sin^2A+cos^2A) = 1
you really just have

-sinx tanx/cosx = -sin^2x/cos^2x = -tan^2x