用洛比达法则
用洛比达法则
用洛比达法则
用洛比达法则
原式=lim(x->0) (x-arcsinx)/(x^3)
=lim(x->0)[1-1/(1-x^2)^(1/2)]/(3x^2)
=lim(x->0) [(1-x^2)^(1/2)-1]/[3x^2*(1-x^2)^(1/2)]
=lim(x->0) (-x^2/2)/[3x^2*(1-x^2)^(1/2)]
=-1/6
分成左右两项,然后等价无穷小替换错的
用洛比达法则
用洛比达法则
用洛比达法则
原式=lim(x->0) (x-arcsinx)/(x^3)
=lim(x->0)[1-1/(1-x^2)^(1/2)]/(3x^2)
=lim(x->0) [(1-x^2)^(1/2)-1]/[3x^2*(1-x^2)^(1/2)]
=lim(x->0) (-x^2/2)/[3x^2*(1-x^2)^(1/2)]
=-1/6
分成左右两项,然后等价无穷小替换错的