A mosquito net over a 7 ft.× 4 ft. bed is 3 ft. high. The net has a hole at the corner on the top through which a mosquito enters the net. It flies and sits at the diagonally opposite bottom corner of the net. Taking the hole as the origin, the length of the bed as the X-axis, its width as the Y-axis, and vertically up as the Z-axis, write the components of the displacement vector.
Similar to what we did in vectors in 2D plane, in 3-D planes also writing components is as good as starting from origin and walking only along the coordinate axis to reach the opposite end.
So here we have set our axis. Let's see how much and on which axis should i walk to reach diagonally opposite point.
So i see if i walk 7 feet along the length (X-axis)and then 3 feet on the negative Z-axis and then 4 feet along the Y-axis then i can reach the diagonally opposite corner.
⇒(7^i+4^j−3^k)