a.

is a proper joint density function if, over its support,
is non-negative and the integral of
is 1. The first condition is easily met as long as
. To meet the second condition, we require

b. Find the marginal joint density of
and
by integrating the joint density with respect to
:


Then


c. This probability can be found by simply integrating the joint density:


He has 576.50 now in his account
Answer:
.
Step-by-step explanation:
The center is at (0,0) so the equation will be like
x^2 + y^2 = r^2 where r = radius of the circle.
from the diagram you can see that r = 4
answer is x^2 + y^2 = 16