1+cos5x sin4x=cos4x sin5x

Question

1+cos5x sin4x=cos4x sin5x

Answer 1

1+cos5x sin4x=cos4x sin5x

cos4x sin5x-cos5x sin4x=1

sin(5x-4x)=1

sinx=1

x=pi/2+2pi n, neZ

Comments

cos5x*sin4x-cos4x*sin5x=-1