Answer:
The most significant issue addressed while ensuring the proper functionality of computer is the working of Operating System.
Explanation:
There are many issues faced while making the computer properly functional. Such as, Memory size, processor speed, software installation etc. while operating system not working properly can cause a significant problem. If operating system is not working properly, the user is unable to use the computer.
So, to make sure the functioning of computer, the significant issue that should be needed to address is Operating System Installation.
You would place it in orbit around Earth, as most X-rays are absorbed by the atmosphere, so you would want the detector outside of the atmosphere to accurately detect the X-rays.
For the view of Exercise 4.18, explain why the database system would not allow a tuple to be inserted into the database through this view.
For reference
For the database of Figure 4.12, write a query to find the ID of each employee with no manager. Note that an employee may simply have no manager listed or may have a null manager. Write your query using an outer join and then write it again using no outer join at all.
OUTER JOIN
select e.ID from employee e left outer join manages m on e.ID = m.ID
where m.manager_id is null;
NO OUTER
select e.ID from employee e where e.ID not in (select m.ID from manages m) or e.ID in (select m.ID from manages m where m.manager_id is null);
let's say they catch-up to each other after t hour.
so
in t hour distance travelled by Renee
d = speed × time = 50t
in t hour distance travelled by Kim
d = speed × time = 60(t-1) + 0×1 = 60(t-1)
Note: here kim didn't covered any distance in first hour and in rest t-1 hour it travelled all distance
now.as distance travelled by both is same so
60(t-1) = 50t
60t -60 = 50t
adding 60 both sides
60t = 50t+60
subtracting 50t both sides
60t -50t = 50t+60 - 50t
10t = 60
dividing by 10 both sides
t = 60/10 = 6
so in 6 hour both will catch-up to each other
