2.
sin3x*cos(-3x+π/4)+cos3x*sin(-3x+π/4) разделим на cos3x получим
tg(3x)* cos(-3x+π/4)+ sin(-3x+π/4) разделим на cos (-3x+π/4) получим
tg(3x)+tg(-3x+ π/4)=0= tg(3x)- tg(3x)+tg(π/4)
3.
tg(x+π/5)=√3
(x+π/5)=π/3
x= π/3- π/5=(5π-3π)/15=2π/15
4.
cos5x+cos5x/sin5x=1+1/sin5x=1+(2√3/)5