Simplify cos180*sin225*cos80/sin170*tan135

Answer 1

what's the problem?

cos 180 = -1
sin 225 = -sin 45 = -1/√2

sin 170 = sin 10 = cos 80
tan 135 = -tan 45 = -1

and you have

(-1)(-1/√2)(cos 80) / (cos 80)(-1) = -1/√2

or -(-sin 45) / -tan 45 = -cos 45 = -1/√2