(sin5x/sinx)-(cos5x/cosx)=(sinx/sin5x)-(cosx/cos5x)
sin5x·cosx-cos5x·sinx/sinx·cosx=sinx·cos5x-cosx·sin5x/sin5x·cos5x
2sin4x/sin2x=-2sin4x/sin10x
1/sin2x=-1/sin10x, sin2x=-sin10x
sin2x+sin10x=0
sin2x+sin10x=2sin(2x+10x)/2·cos(2x-10x)/2=0
sin6x·cos4x=0
6x=πn, 4x=πn. n∈Z
x=πn/6 , x=πn/4, n∈Z