a plane is flying directly away from a place at an altitude of 4 miles. the distance between the plane and the place is increasing at a rate of 717 miles per hour.
how fast is the plane traveling at the moment the distance between the plane and the place is 8 miles?
一架飛機直接飛離海拔4英里的地方。 飛機與地方之間的距離以每小時717英里的速度增加。
飛機與地點之間的距離為8英里時,飛機的行進速度為多快?
請問這個要怎麼解呢