假设t时,距离最近
那么t时,车走出100t ,台风离A城 200-25t
距离为d
d^2= (100t)^2+(200-25t)^2
=10000t^2+40000+625t^2-10000t
=10625t^2-10000t+40000
d^2取最小值t=10000/(2*10625)=1000/2125
=200/425=40/85=8/17
d=194.03千米
假设t时,距离最近
那么t时,车走出100t ,台风离A城 200-25t
距离为d
d^2= (100t)^2+(200-25t)^2
=10000t^2+40000+625t^2-10000t
=10625t^2-10000t+40000
d^2取最小值t=10000/(2*10625)=1000/2125
=200/425=40/85=8/17
d=194.03千米