y' = x'(sinln x - cosln x)+ x(sinln x - cosln x)'=

=(sinln x - cosln x)+x(coslnx *ln'x+sinlnx *ln'x)=

=(sin ln x - cosln x)+x(coslnx /x+sinlnx  /x)=sinln x - cosln x+coslnx +sinlnx=2sinlnx