x->0arcsinx = x +(1/6)x^3+o(x^3)x-arcsinx = -(1/6)x^3+o(x^3)lim(x->0) [ 1/(xarcsinx) -1/x^2 ]=lim(x->0) (x-arcsinx)/(x^2.arcsinx) =lim(x->0) (x-arcsinx)/x^3=lim(x->0) -(1/6)x^3/x^3=-1/6
