Answer:
a.2:7
b.7:9
c.4:5
hope it helps
Explanation -
a. as original ratio is 10/35 , we reduce it to 2:7.
b. as original ratio is 35/45 , we reduce it to 7:9
c. as original ratio is 40:50 , we reduce it to 4:5
Because I've gone ahead with trying to parameterize
directly and learned the hard way that the resulting integral is large and annoying to work with, I'll propose a less direct approach.
Rather than compute the surface integral over
straight away, let's close off the hemisphere with the disk
of radius 9 centered at the origin and coincident with the plane
. Then by the divergence theorem, since the region
is closed, we have

where
is the interior of
.
has divergence

so the flux over the closed region is

The total flux over the closed surface is equal to the flux over its component surfaces, so we have


Parameterize
by

with
and
. Take the normal vector to
to be

Then the flux of
across
is




bro what is this i have never seen this
Polygon Diagonals. The number of diagonals in a polygon = n(n-3)/2, where n is the number of polygon sides. For a convex n-sided polygon, there are n vertices, and from each vertex you can draw n-3 diagonals, so the total number of diagonals that can be drawn is n(n-3).