lim(x->0) [√(1+tanx) -√(1+sinx) ]=lim(x->0) [(1+tanx) -(1+sinx) ]/[√(1+tanx) +√(1+sinx) ]=(1/2)lim(x->0) [(1+tanx) -(1+sinx) ]=(1/2)lim(x->0) ( tanx -sinx) =0
