By Green's theorem,

where
is the circle
and
is the interior of
, or the disk
.
Convert to polar coordinates, taking

Then the work done by
on the particle is

The left hand side of the equation is a difference of two squares and may be factored out as follows,
(x - 4)(x + 4) > 0
They may be individually taken as,
x - 4 > 0 ; x > 4
x + 4 > 0 ; x < -4
Thus, the answer to this item is letter A.
The circumcenter of a triangle is the point in the plane equidistant from the three vertices of the triangle. so I believe it is A. True..
To find the volume of the following Firewood, we would do this:
4 * 4 * 8 = 128 cubic feet
Therefore, the volume of the firewood is 128 cubic feet.
Make sure to mark as brainiest.