[3cos5x-4cos5x*cosx]/[3sin5x-4sin5xcosx]=tg17x cos5x(3-4cosx)/sin5x(3-4cosx)=tg17x cosx≠3/4 ctg5x=tg17x tg17x-tg(π/2-5x)=0 sin(22x-π/2)/cos17x*cos(π/2-5x)=0 cos17x≠0 U cos(π/2-5x)=sin5x≠0 sin(22x-π/2)=0 22x-π/2=πn 22x=π/2+πn x=π/44+πn/22