-v3cos(2.5x)+sin(2.5x)=0 /(cos(2.5x) -v3+tg(2.5)x=0 tg(2.5)x=v3 2.5x=pi/3+pi*n (/x=pi/3)/2.5+pi*n/2.5 x=pi/7.5+pi*n/2.5