x'=sint-t+t(Cost-1),
x'(0)=0,
y'=1+Sint,y'(0)=1,
z'=2t,z'(0)=0,
此切线的方向矢量在x,z轴上的分量是0,说明切线同时垂直于x,z轴,即平行于y轴,
x(0)=0,y(0)=-1,z(0)=1,
所以切线方程是
x=0,y=-1-t,z=1