Hello can i get a step by step for this Problem 7. Car B is 30 miles directly east of Car A and begins moving west at 90 mph. At the same moment car...

Hello can i get a step by step for this

Problem 7.16. Car B is 30 miles directly east of Car A and begins moving west at 90 mph. At the same moment car A begins moving north at 60 mph. What will be the minimum distance between the cars and at what time t does the minimum distance occur ?

Hint: Choose a good coordinate system and minimize the square of the distance.