12.5 Drawing a Locus

A locus is a set of points that follow a given rule. The plural of locus is loci. You need a ruler and compass to draw a locus accurately

12.4 Enlarging Shapes

When you enlarge a shape, all the lengths of the sides of the shape increase in the same proportion. This is called the scale factor. All the angles in the shape stay the same size.

When you describe an enlargement you must give:

• The scale factor of the enlargement.
• The position f the centre of the enlargement

12.3 Transforming Shapes

You can use a combination of reflections, translations and rotations to transform a shape. You can also describe the transformation that maps an object onto its image.

To describe a reflection you must give: 

• the equation of the mirror line

To describe a translation you must give: 

• the column vector

To describe a rotation you must give: 

• the centre of rotation
•  the number of degrees of rotation (or fraction of whole turn)
• the direction of the reaction (clockwise or anticlockwise)

           

12.2 Solving Transformation Problems

When a shape undergoes any of these three transformations it only changes its position. Its shape and size stay the same. Under these three transformations, an object and its image are always congruent.

When you reflect a shape on a coordinate grid you need to know the equation of the mirror line.

All vertical lines are parallel to the y-axis and have the equation x=’a number’

All horizontal lines are parallel to the x-axis and have the equation y=’a number’

Some examples are shown on the grid on the right.

When you rotate a shape on a coordinate grid you need to know the coordinates of the centre of rotation, and the size and direction of the turn.

When you translate an example of a column vector: 4,5

The top number states how many units to move the shape right (positive number) or left (negative number). The bottom states how may units to move the shape up (positive number) or down (negative number)

For example: 

(4,5) means : ‘move the shape 4 units right and 5 units up’

(-2,-3) means: ‘move the shape 2 units left and 3 units down’

You can see any these three transformations to solve all sorts of problem

12.1 Tessellating Shapes

A tessellation is a pattern of identical shapes. You can make your own tessellation by fitting copies of a shape together, without gaps or overlap. You say the shape tessellates, or a tessellating shape. Here are some examples of shapes that tessellate with themselves.

Here are some examples of shapes that do not shape with themselves. There are gaps between the shapes.

When you make a tessellation you can move the shape by translating, rotation or reflecting it. 

Many tessellations are made by repeating a shape and using half-turn rotations of the same shape.

For example, this triangle

and using half-turn rotations of the same triangle fit together exactly to make a tessellation like this:

In any tessellation, the sum of the angles at the point where the vertices of the shapes meet is 360 degree. Look closely at three of the tessellations above.

Water Cleaning Projet

FAPIPS Water Cleaning Organization from Al-Taqwa College Indonesia would like to introduce our plan

Program: Water Cleaning

Name of organization: FAPIPS water cleaning

Slogan: Air bersih, kita senang.

Aim: We want to help the people who live nearby the Citarum river get clean water.

Location: Citarum River, Bekasi, Indonesia

How to reach there: Voluntary transportation with the help of google map.

Reason: The people of Citarum are lacking of clean water.

Problem: Citarum river is covered in rubbish so that no clean water can be obtain.

Solution: Clean the river from the rubbish.

Steps:
1. Persuade the society to cooperate by stop littering.
2. Pick up all the rubbish in the river in order to clean it.
3. Cooperate with a company in Citeureup to recycle the rubbish.
4. Get a sponsor.
5. Cooperate with the government to support our program.

((FAPIPS stands for Fatimah, Angela, Putri, Indah, Prstina, Shoffa. These are the main members.)

What Should You Do as The Next President?

Dear Mr. ....,

Our names are Indah and Pristina. We would like to ask you some questions since we know that you are one of the nominees of Indonesia’s Next Presidents.

As we know that Indonesia is going to have a democracy party on April 9 2014. Every citizen has the right to choose their own choice for a leader. There are many president candidates that are willing to be presidents and you are one of them.

If you really are willing to be the next President of Indonesia, then we have some questions for you. 

Us, as Indonesian citizens surely want a leader who can develop Indonesia and make Indonesia as a better country.

1.  In your opinion, are you really sure to be the next president of Indonesia 2014-2019 that is going to be chose by the citizens through the election?

According to political observer from University of Indonesia, Andrinof Chaniago predicted that the amount of citizens who don’t take the right to vote their leader will increase.

“The amount of citizens who don’t take the right to vote can increase from 35 up to 40 percent.” said Andrinof when he was contacted by Kompas.

We think that this might be the proof that Indonesian citizens don’t care about the future of Indonesia. Do you think you can be the next president of Indonesia in this condition?

And then our next question is:

2.  What is the first thing that you will do when you become the president of Indonesia?

We know that being the president of Indonesia with 240 million citizens and many islands can’t be easy. To us, it’s very hard to just be a leader in the classroom. If being a leader in a classroom is hard, how about ruling millions of citizens from many tribes and cultures? We can’t imagine it, it must be really hard. It’s a big challenge.

We want the next president of Indonesia to not take the wrong step in every of his action and duty. The next president of Indonesia should be sure and aware of all the risks from his deed. We really want to have Indonesia developed. Just like Japan and Singapore. If Japan and Singapore can be developed then Indonesia should be able to be developed too!

The third question: 

3.Can you assure that when you become the next President of Indonesia, Indonesia will be free from corruption?

It's pathetic to see and hear the legendary and phenomenal news on the television until very recently.Whenever there is a new hot topic, it must be about corruption. Corruption news has been the trending topic of Indonesia. Indonesia must be lead by a leader who has a strong faith and iman. Corruption is a shameful act. Verily, corruption disadvantage not only oneself, but every citizen of Indonesia. If the next leader is a corruptor, what will happen to the future of Indonesia? One can't be a president of the country, if he can't even be a president to himself. A leader must be firm and be a role model to the citizens. 

It's an honor for us as students, if you can answer our 3 questions.

Because we hope that Indonesia will have a deserving President to lead Indonesia. So that one day, Indonesia can be a developed country.

Thank You. 

Sincerely,

Pristina and Indah. 

IT

WAN Technology

Stands for Wide Area Network is similar to a Local Area Network (LAN), but it's a lot bigger. Unlike LANs, WANs are not limited to a single location. Many wide area networks span long distances via telephone lines, fiber-optic cables, or satellite links. They can also be composed of smaller LANs that are interconnected. The Internet could be described as the biggest WAN in the world.

Frame Relay –is A packet-switched technology of 64Kbps up to 45Mbps (T3).it provides features for dynamic bandwidth allocation and congestion control.

PPP - PPP can be used to create point-to-point links between different vendors’ equipment. 

PPP Facts

• It can be used on a wide variety of physical interfaces including asynchronous serial, synchronous serial (dial up), and ISDN.
• It supports multiple Network layer protocols, including IP, IPX, AppleTalk, and numerous others.
• Optional authentication is provided through PAP (2-way authentication) or CHAP (3-way authentication).
• It supports multilink connections, load-balancing traffic over multiple physical links.
• It includes Link Quality Monitoring (LQM) which can detect link errors and automatically terminate links with excessive errors.
• It includes looped link detection that can identify when messages sent from a router are looped back to that router. This is done through routers sending magic numbers in communications. If a router receives a packet with its own magic number, the link is looped.

PPP uses two main protocols to establish and maintain the link.

TCP/IP (7 OSI Layers)

Transmission Control Protocol/Internet Protocol, the suite of communications protocols used to connect hosts on the Internet. TCP/IP uses several protocols, the two main ones being TCP and IP. TCP/IP is built into the UNIX operating system and is used by the Internet, making it the de facto standard for transmitting data over networks. 

The OSI, or Open System Interconnection, model defines a networking framework to implement protocols in seven layers. Control is passed from one layer to the next, starting at the application layers in one station, and proceeding to the bottom layer, over the channel to the next station and back up the hierarchy.

DNS                                                                                                                            

Short for Domain Name System (or Service or Server), an Internet service that translate domain names into IP addresses. Because domain names are alphabetic, they're easier to remember. The Internet however, is really based on IP addresses. Every time you use a domain name, therefore, a DNS service must translate the name into the corresponding IP address.                                                                                                                                                                   

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             

11.4 Practical Examples

Here are some real-lufe examples of uses of percentages.

• If you buy something and sell it, the difference between the two price is a profit or a loss. It is given as a percentage of the buying price.
  If you buy something for $20 and sell it for $15 you make a loss of 5% or 25%
• When you buy something you may be offered a discount.
  This is a reduction in the price. It is usually given as a percentage.
  If the price is normally $20 and you get a 10% discount, you only pay %18. 
• If a bank helps you to buy an item, you may have to pay back more than you borrow.
  This is the interest that the bank charges. It is given as a percentage of the cost.
  If the car costs $20000 and the rate of interest is 3%, you will pay $20600.
• If you buy something the price may include the tax. This is called a purchase tax.
  When you earn money you may have to pay tax on what you earn . this is called income tax.

WORKED EXAMPLE:

A man earns $45000 in a year 

He can earns $16000 withoutpaying any tax. He pays 24% tax on anything above $16000.

a) work out how much tax he pays.

b) what percetage of his income does he pay in income tax?

a) 45000 - 16000 = 29000

24% of 29000 = 6960

So he pays $6960

b) 6960 / 45000 x 100 = 15.5%

exercise 1:

1) The percentage profit is a percentage of 240

A woman bought an ols chair for $240. she told it for $300 

work out the percentage profit.

exercise 2:

1) a bottle of grape juice costs $6.50

if you buy six bottles you can get 10% discount.

Work out how much you save if you buy six bottles?

---

You also may check this website below:

http://www.teacherschoice.com.au/Maths_Library/Money/profit_and_loss.htm
http://www.emathzone.com/tutorials/everyday-math/profit-and-loss.html

Check this out:

11.3 Percentage Changes

You can use percentages to describe a change in a quality. It could be an increase or a decrease. A percetage change is always calculated as a percentage of the initial value. The initial value is 100%. It is important to choose the correct value to be 100%

Worked Example :

In May 800 people visited a museum. In June 900 People visited. In July, the number was 800 again. Work out:

a) the percentage increase from May to June

b) the percentage decrease from June to July

a)  100% = 800

The increase is 100. The percentage is increase is 100/800 x 100 = 12.5%

b) 100% = 900

The decrease is 100. The percentage decrease is 100/800 x 100 = 11.1%

Exercise 1:

Here are the prices of three items in Alain's shop.

a) Game $40 

b) Phone $120

c) Computer $500 

Alain increase all the prices by $10. Find the percentage increase for each item.

Exercise 2:

"The price after the sale is $20000 again"

The price of a car was $20000. In a sale, the price decreased by 4% After the sale it increased by 4%

a) what mistake has Ahmad made?

b) What is the correct price after the sale?

 ---

In order to be more understand you may check this web:

http://www.mathgoodies.com/lessons/percent/change.html

http://www.mathsisfun.com/numbers/percentage-change.html

http://math.about.com/od/prealgebr1/a/percent.htm

And Youtube :D 

11.2 Comparing Different Quantities

You will often need to compare that are different sizes.
Suppose that, in one school, 85 students took an exam and 56 passed.
In another school, 237 students took an exam and 147 passed.
Which school did better? It is hard to say because each school had a different number of students.

The worked example shows how to use percetages to help to answer question like this:

WORKED EXAMPLE 1:

In school A, 85 students took a mathematics exam and 56 passed.
In School B, 237 stundets took an mathematics exam and 147 passed.
Which school had a better pass rate?

59  out of 85 = 59/85 = 69%
59/85 = 0.694... = 69% to the nearest whole number.

147 out of 237 = 147/237 = 62 %
147/237=0.620... = 62% to the nearest whole number.

The pass rate in school B is better by seven percentages points!
The difference between 62% and 69% is given in 'percentage points'

Exercise 1:

There were 270 people in a cinema. There were 168 women and 102 men.
There were 152 people in the theatre. There were 78 women and 74 men.

a)  Work out the percentage of women in each venue
b)  Work out the percentage of men in each venue

Exercise 2:

This table shows the results of a survey in a factory.

	Smoker	Non-Smokers	Total
Men	12	64	76
women	9	32	41

a) what percentage of men are smoker?

b) Compare the percentages of men and women who are non-smokers?

---

In order to understand you may check this website:

http://www.excellup.com/

11.1 Using Metal Methods

some percentages are easy to find because they are simple fractions.
There are examples of these on the first page of this unit.

You can use the easy ones to work out more complicated percentages.
You can often do this quite easily. You do not always need a calculator.

If you know 10% you can find any multiple of 10%

WORKED EXAMPLE:

There are 4600 people in stadium. 58% are males. How many is that?

100% = 4600

50% = 50% + 10% - 2% 
These are all easy percetages to find

50% = 2300
50% = 1/2

10% = 460
1/10 is easy. Just devide by 10

1% = 46
Divide 10% by to find 1%

58% = 2300 + 460 - (2 x 46) = 2668  
Do this sum in your head or on paper

Exercise 1:

Work Out:

a) 35% of 84
b) 49% of 230
c) 77% of 4400

Exercise 2:

Work Out:

26% of 78 = 20.28

Use this fact to find:

a) 52% of $78


b) 9.5% of 256

You may check this website if you still didn't understand:

http://www.mathsisfun.com/percentage.html
http://www.homeschoolmath.net/teaching/percent/percent_of_number_mental_math.php

Youtube:

Network Topology

Topology of a network is its physical layout. There are basically two components to a network. Devices on the network that want to share resources or information and the medium which allows the communication to occur. A Network Topology is the physical layout of the computers, servers, and cables. There are four topologies mentioned in this learning item: star, bus, mesh, and ring. You can add wireless to the list as a growing popular option for network topology.


Bus topology

 is one which consists of all of the workstations connected to a single cable. This topology is frequently in coax, or 10Base2, networks. The bus network has a terminator on each end of the network. If a terminator is not present or if there is a problem in the line (e.g. NIC card failure, network disconnected from PC), all workstations on that line lose connectivity.

The typical Bus network uses coax as its cable. Coax is a cable similar to what you use for your cable TV. Coax is also referred to as 10Base2.

The upside to using coax is that it is inexpensive, easy to install, and is not as susceptible to electromagnetic interference as twisted pair cable is.

The downside for a coax network is the speed is limited to 10 Mbps (Megabits per second) and that is an interruption occurs in the cable, all of the nodes (workstations) on the cable will lose connectivity. If a NIC fails or a cable is disconnected at any of the points in the network, it will not be terminated properly so all of the computers will lose connectivity to the network.



Mesh topology

A mesh topology is the best choice when you require fault tolerance, however, it is very difficult to setup and maintain.

There are two types of mesh network: full mesh and partial mesh. A full mesh is one which every workstation is connected to the other ones in the network. In a partial mesh, the workstations have at least two NICs with connections to other nodes on the network. Mesh networks are commonly used in WANs.

Computer Networks

 

Computer NetworksNetworks are collections of computers, software, and hardware that are all connected to help their users work together. A network connects computers by means of cabling systems, specialized software, and devices that manage data traffic. A network enables users to share files and resources, such as printers, as well as send messages electronically (e-mail) to each other.

Computer networks fall into two main types: client/server networks and peer-to-peer networks. A client/server network uses one or more dedicated machines (the server) to share the files, printers, and applications. A peer-to-peer network allows any user to share files with any other user and doesn’t require a central, dedicated server.
The most common networks are Local Area Networks or LANs for short. A LAN connects computers within a single geographical location, such as one office building, office suite, or home. By contrast,Wide Area Networks (WANs) span different cities or even countries, using phone lines or satellite links.

Networks are often categorized in other ways, too. You can refer to a network by what sort of circuit boards the computers use to link to each other – Ethernet and Token-Ring are the most popular choices. You can also refer to a network by how it packages data for transmission across the cable, with terms such as TCP/IP (Transmission Control Protocol/Internet Protocol) and IPX/SPX (Internet Package eXchnage/Sequenced Package eXchange).
Steps to Setting-Up a Network.All networks go through roughly the same steps in terms of design, rollout, configuration, and management.
Designing Your NetworkPlan on the design phase to take anywhere from one to three working days, depending on how much help you have ad how big your network is.
Here are the key tasks:

• Settle on a peer-to-peer network or a client/server network.
• Pick you network system software.
• Pick a network language.
• Figure out what hardware you need.
• Decide on what degree of information security you need.
• Choose software and hardware solutions to handle day-to-day management chores.

Rolling Out Your NetworkRolling out your network requires the following steps:

• Run and test network cables.
• Install the server or servers if you’re setting up a client/server network. (If you are setting up a peer-to-peer network, you typically don’t have to worry about any dedicated servers.)
• Set up the workstation hardware.
• Plug in and cable the Network Interface Cards (NICs – these connect the network to the LAN).
• Install the hub or hubs (if you are using twisted-pair cable).
• Install printers.
• Load up the server software (the NOS, or Network Operating System) if your network is a client/server type.
• Install the workstation software.
• Install modem hardware for remote dail-up (if you want the users to be able to dial into the network).
• Install the programs you want to run (application software).

Configuring Your NetworkNetwork configuration means customizing the network for your own use.

• Creating network accounts for your users (names, passwords, and groups).
• Creating areas on shared disk drives for users to share data files.
• Creating areas on shared disk drives for users to share programs (unless everyone runs programs from their own computer).
• Setting up print queues (the software that lets users share networked printers).
• Installing network support on user workstations, so they can "talk" to your network.

Source link : http://tecschange.org/classic/networks/network-syllabus.html

Comment: Computer network has been given us many information and help us to do our work. But, you need to be careful when you using network.

Regard,
Ndah F