Question

qual e o resultado de sen 15° . cos 15° ???

Answer 1

sen2x = 2senx cosx

ou seja

2senx cosx = sen2x

sen15°.cos15° = (1/2).2sen15°.cos15° = 1/2. sen(2.15°) = 1/2 . sen30° =

1/2 . 1/2 = 1/4