Sin(Arccos(-5/13)).cos(arcsin(4/5))

Question

Sin(Arccos(-5/13)).cos(arcsin(4/5))

Answer 1

Sin(Arccos(-5/13)).cos(arcsin(4/5))=

cos(arccos(-5/13) = -5/13⇒sin(arccos(-5/13) = +√(1-(-5/13)²) = +12/13.
sin(arcsin(4/5) = 4/5⇒cos(arcsin(4/5) = +√(1-(4/5)²) = +3/5.
Теперь умножаем( если там стоит знак умножения) = 36/65.