Question

Упростите выражение: cos(arccosx+arccosy)

Answer 1

cos(arccosx+arccosy)=cos[arccos(xy-√(1-x²)*√(1-y²)]=xy-√(1-x²)*√(1-y²)

Answer 2

cos(arccosx+arccosy)=cos(arccos(xy-√(1-x^2)√(1-y^2))=xy-√(1-x^2)√(1-y^2)