It’s in the thousands place
First, set the coordinate points on a graph, and joint them to form a graph
By looking at the graph we can see that:
width : 3
length: 6
Area of a rectangle : Length x width : 6 x 3 = 18
Always because the sum of x and y is 180 degrees. If x and y are right angles, then x and y are supplementary angles. Never because the sum of x and y has to be 90 degrees. If x and y are complementary angles, then y is a right angle.
For
to be conservative, we need to have



Integrate the first PDE with respect to
:

Differentiate with respect to
:

Now differentiate
with respect to
:

So we have

so
is indeed conservative.