12.2. VECTOR FIELDS 219

You can see how the arrows indicate the motion of this fluid.

Example 12.2.2 Draw a picture of the vector field (y,x) for the velocity of a fluid flowingin two dimensions.

Here is another such example.

Example 12.2.3 Draw a picture of the vector field (ycos(x)+1,xsin(y)−1) for the ve-locity of a fluid flowing in two dimensions.