By Stokes' theorem, the line integral of over
is given by the surface integral of the curl of
over
, where
is the region of intersection of the plane
and the cylinder
with
having positive/upward orientation.
Parameterize by
with and
.
Take the normal vector to to be
The curl of is
Then the line integral is equivalent to
Answer:
Rate of change of the area of the square is 42 units at t = 2.
Step-by-step explanation:
We note that the area of the square is given by: but we aim to find
. But we can use the chain rule to pull out that dA/dt. Doing so gives us:
Now, (by the power rule and
But since we have "x" and not "t", we want to find what x is when t = 2. Substituting t = 2 gives us x(2) = 3(2) + 1 = 7.
So, finally, we see that: