Answer:
The area of the sphere in the cylinder and which locate above the xy plane is 
Step-by-step explanation:
The surface area of the sphere is:

and the cylinder
can be written as:


where;
D = domain of integration which spans between 
and;
the part of the sphere:

making z the subject of the formula, then :

Thus,


Similarly;


So;





From cylindrical coordinates; we have:

dA = rdrdθ
By applying the symmetry in the x-axis, the area of the surface will be:





![A = 2a^2 [ cos \theta + \theta ]^{\dfrac{\pi}{2} }_{0}](https://tex.z-dn.net/?f=A%20%3D%202a%5E2%20%5B%20cos%20%5Ctheta%20%2B%20%5Ctheta%20%5D%5E%7B%5Cdfrac%7B%5Cpi%7D%7B2%7D%20%7D_%7B0%7D)
![A = 2a^2 [ cos \dfrac{\pi}{2}+ \dfrac{\pi}{2} - cos (0)- (0)]](https://tex.z-dn.net/?f=A%20%3D%202a%5E2%20%5B%20cos%20%5Cdfrac%7B%5Cpi%7D%7B2%7D%2B%20%5Cdfrac%7B%5Cpi%7D%7B2%7D%20-%20cos%20%280%29-%20%280%29%5D)
![A = 2a^2 [0 + \dfrac{\pi}{2}-1+0]](https://tex.z-dn.net/?f=A%20%3D%202a%5E2%20%5B0%20%2B%20%5Cdfrac%7B%5Cpi%7D%7B2%7D-1%2B0%5D)


Therefore, the area of the sphere in the cylinder and which locate above the xy plane is 
Answer: Matrix B is non- invertible.
Step-by-step explanation:
A matrix is said to be be singular is its determinant is zero,
We know that if a matrix is singular then it is not invertible. (1)
Or if a matrix is invertible then it should be non-singular matrix. (2)
Given : A and B are n x n matrices from which A is invertible.
Then A must be non-singular matrix. ( from 2 )
If AB is singular.
Then either A is singular or B is singular but A is a non-singular matrix.
Then , matrix B should be a singular matrix. ( from 2 )
So Matrix B is non- invertible. ( from 1 )
80 is the correct answer hope it helps
C cause the sport lovers option is biased
Answer:
The answer is A.Circle
Step-by-step explanation: