Csr. 4 Applied Math 40S Look Who S Talking

cSr. 4 Applied Math 40S “Look who’s talking”

This assignment is out of 9 marks. When answering applied math questions the process of finding the answer is of great importance. Always be sure to explain how you got your answer. This may include showing all your work or briefly explaining your answer in sentences.

Essential skill -Directed and non-directed matrices

This question must be done on graph paper, and in pencil

1) Draw a network diagram that represents the communication between 4 computers (A, B, C and D) shown in this directed matrix. A B C D A 轾0 2 1 0 B 犏1 1 0 1 X= 犏 C 犏1 1 2 1 犏 D 臌2 0 1 0 (2 marks)

2) a) Show the matrix operation for the matrix in 1) which will determine the communication between A, B, C and D through exactly two relays. (1 mark) b) What is the entry in row 2 column 3 of X2? (1 mark)

There are six people at a party. Their names are Ann, Bryn, Colin, Dil, Eric and Fran.

The network below shows which people spoke to each other at the party.

1) Draw a matrix, called X, which shows which people talked to which other people. Use numbers to indicate the number of times people talked to each other. A zero indicates they did not speak. A one indicates they spoke once, a two indicates they spoke twice. (1 mark) 2) What does the matrix X2 represent when you a considering people talking at the party? Give an example. (1 mark) 3) What does X2 + X represent when you a considering people talking at the party? Give an example. (1 mark) 4) Using the above network, Ann wants to get a message to Bryn. What is the least number of people that will be involved including Ann and Bryn? How many different ways can this be done? Who is involved? (1 mark)

5) What is the value in row 2 column 3 of X9? (1 mark)