=интеграл (4cos2 x /(4sin^2 x cos^2 x)dx=integral (4cos2x /(2sinx cosx)^2dx=integral (4cos2x /sin^2 (2x)) dx=(1/2)*4*integral (1/sin^2(2x)d(sin(2x)=2*(-1)*1/sin2x+c=-2/sin2x+c
2) =1/3integral (cosx+2/3-3/cosx)dx=1/3(int cosxdx+2-3int1/cosx dx)=1/3(sinx+2x+int(sin^2x+cos^2x)/cosx ???