Answer:
The expression is :
π[cd) + π(g,h) ],[π(e,f)+π(a,b)])
We will use foreign key and primary key
Answer:
Explanation:
When programming in an OOP language classes are created to represent real-life objects, people, places etc. from the real world. Programming in the general allows you to cut down your code and making it more efficient by applying the same necessary functions to all of the objects that classify under the same category. For example by programming "in the general" and creating an Animal class you can create all of the functions/behaviors that animals tend to have. Then you can apply these functions/behaviors to various animals such as a Cat, Dog, Horse, etc. But if you program in the specific you cannot apply a Cat class to a Dog since they are not the same thing.
Answer:
The Variable is out of scope
Explanation:
In programming variables exists with scopes This could be local or global. When a variable is declared as a global variable it is available to all methods and procedures in the program. Java programming language as well as C++ and several others use the open and close braces to define the scope in programs. consider the following example
<em>public class ANot {</em>
<em> public static void main(String[] args) {</em>
<em> int i = 0;</em>
<em> while ( i<10){</em>
<em> int sum = 0;</em>
<em> sum = sum+i; </em>
<em> }</em>
<em> }</em>
<em>}</em>
In this example, the variable i is global and can be assessed within the while loop but the variable sum is local to the while loop and cannot be assessed outside of it
The answer is a Mesh topology. This method connects every device to each other device in the network. A wired full-mesh topology is not as common as it is impractical and highly expensive. A partial mesh topology offers redundancy if one of the connections goes down and usually uses a connecting medium such as a router to eliminate cables and expensive PCI NIC's.
Here are the main functions of an operating system:
1) Manage the resources of the device
The operating system controls how much of each resource is distributed, and it controls things like the processing unit and memory.
2) Establish a interface for the user of the device
The operating system must classify what the classes of the script/code have to do and what they implement.
3) Service application software
The operating system must service each application that is downloaded onto the device. It must balance it's use of storage between apps.
