lim x趋向0 [x(1-cos2x)]/(5x-sin5x)＝lim x趋向0 [x2(sinx)^2]/(5x-sin5x)=lim x趋向0 [2x^3]/(5x-sin5x)=lim x趋向0 [6x^2]/(5-5cos5x)＝lim x趋向0 [12x]/(25sin5x)＝lim x趋向0 [12]/(125cos5x)＝lim x趋向0 12/...