x=(t+1/t)sinθ => sinθ =x/(t+1/t) ①y=(t-1/t)cosθ => cosθ=y/(t-1/t) ②两式平方相加,得到x^2/(t+1/t) ^2+y^2/(t-1/t) ^2=1其中(t+1/t) ^2-(t-1/t) ^2=4>0所以方程表示焦点在X轴,c^2=4,坐标为,长半轴a=|t+1/t|...