Final answer:
The most important way to view behind a vehicle is by using rear-view and side mirrors, with diverging mirrors being common in cars for a wider field of vision but with the disadvantage of reducing object size.
Step-by-step explanation:
The most important way to see the sides and rear of your vehicle is by using the rear-view mirrors and side mirrors. Diverging mirrors, also known as convex mirrors, are often used for rear-view mirrors in vehicles because they allow a wider field of vision, enabling drivers to see more of the space behind them.
However, the main disadvantage of using diverging mirrors compared to flat mirrors is that they diminish the size of the reflected objects, making it more difficult to judge the distance and speed of approaching vehicles.
Furthermore, it is not necessary to project a real image onto a screen to see it; a virtual image as seen in mirrors is sufficient for our eyes to perceive it. To see the back of your head with mirrors, you would need at least two mirrors positioned at the correct angles to reflect the view from behind your head into your line of sight.