Question

Sin205Cos85-Cos205Sin85

Answer 1

Remember that :

sin a . cos b - cos a. sin b = sin (a-b)

so :

sin 205. cos 85 - cos 205 . sin 85
= sin (205 - 85)
= sin 120
= sin ( 180-60)
= sin 60
= ½ √3

Hopefully helpfull... :)