x't=e^t(cost-sint)y't=e^t(sint+cost)z't=e^tds=√[(x't)^2+(y't)^2+(z't)^2] dt=√3 e^t dt把各参数带入原积分原积分=∫√3 e^t dt /(2e^2t)=(√3/2)∫(t->t0) e^(-t)dt=(√3/2)[e^(-t)-e^(-t0)]