Given the following binary relations R on two sets, for each relation:

• Draw the arrow diagram of R.
• Is R a function, and why?
• If R is a function, determine if it is injective or surjective. Is the function bijective? Justify your answers.

1. 1. R = {(a, 3), (c, 1)} on domain {a, b, c} and codomain {1, 2, 3}
2. 2. R = {(1, a), (3, c), (2, b)} on domain {1, 2, 3} and codomain {a, b, c}
3. 3. R = {(a, b), (b, c), (d, b), (c, c)} on domain {a, b, c, d} and codomain {a, b, c, d}
4. 4. R = {(a, y), (b, z)} on domain {a, b} and codomain {x, y, z}

The officers of a high school senior class are planning to rent buses and vans for a class trip. Each bus can transport 35 students, requires 3 ​chaperones, and costs ​$ 1,200 to rent. Each van can transport 7 ​students, requires 1​ chaperone, and costs ​$ 90 to rent. Since there are 280 students in the senior class that may be eligible to go on the​ trip, the officers must plan to accommodate at least 280 students. Since only 30 parents have volunteered to serve as​ chaperones, the officers must plan to use at most 30 chaperones. How many vehicles of each type should the officers rent in order to minimize the transportation​ costs? What are the minimal transportation​ costs?

How do you solve this word problem?

T is a tree graph on 10 vertices, each is labled with an integer from 1-10. There are four leaves: 1, 2, 3, and 4.

1. What is the number of possible trees, such that the vertices labeled 1, 2, 3, and 4 are leaves, and the other labeled vertices can be either a leaf or not.

1. What is the number of possible trees, such that only 1, 2, 3, and 4 are leaves.

A pizza place is having a special: 10 medium pizzas for $50. They only allow you to choose one of their 6 different specialty pizzas though, with no substitutions. You and 6 friends are having a get-together (so 7 people altogether), and you decide to order pizza for the group. Each person gets to choose one type of pizza, and then you are responsible for choosing the remaining 3. Once all 7 people have chosen their pizza, how many total ways are there for you to complete the order?

Use Euler method (as explained on the white board) to solve numerically the following ODE:

dy/dt=y+t. y(0)=1

You can select the step size. Choose n=3. solve this by hand on a paper and with the aid of Matlab.

Let f(x) = x - R/x and g(x) = Rx - 1/x

a) Derive a Newton iteration formula for finding a root of f(x) that does not involve 1/x_n. To which value does the Newton iterates x_n converge?

b) Derive a Newton iteration formula for finding a root of g(x) that does not involve 1/x_n. To which value does the Newton iterates x_n converge?

Reflect on the concept of polynomial and rational functions. What concepts (only the names) did you need to accommodate these concepts in your mind? What are the simplest polynomial and rational function you can imagine? In your day to day, is there any occurring fact that can be interpreted as polynomial and rational functions? What strategy are you using to get the graph of polynomial and rational functions?

The Learning Journal entry should be a minimum of 400 words and not more than 750 words.

Solve the following ODE using Laplace Transforms
?̈+?̇+3?=0;?(0)=1; ?̇(0)=2

Solve the heat equation (in one dimensional case) for c^2=9, the following boundary and initial conditions:

u(0,t)=u(2Pie,t)=0

u(x,0)=5sinx = 2sin5x

GTA Construction Corporation constructed two buildings near the San Andreas fault line. The probability that either of these buildings will experience an earthquake is 4.6 percent. However, if one building experiences an earthquake, the probability that the second building will experience an earthquake is 57 percent. What is the probability (in percent) that both buildings will experience earthquake damage?

IMB Computing creates motherboards for cellphones at their campuses in Seattle and San Diego. The company is worried about computer hackers and hired a consultant to evaluate their risk. The consultant estimated that the San Diego campus has a 12.1 percent chance of being hacked. The consultant also noted that the Seattle location has a 24.4 percent chance of digital hacking. IMB would asks the consultant, what is the probability (in percent) that both campuses will suffer hacking related crime in any given year?

Hishiba Company assembles hard drives and has plants in both the South and the North, spaced about 3,000 miles apart and connected by light rail. Hishiba is worried about local rain causing flooding at their plants. The probability that in any given year a flood will damage the North plant 5.1 percent. The probability that in any given year a flood will damage the South plant is 13 percent. What is the probability (in percent) that at least one of the plants will be damaged by flood in any given year?

Your job is to fully staff your facility at the lowest cost. The facility must have at least 2 people w working from 6am-8pm Monday thru Friday and at least 1 person working from 10am to 6 pm on Saturdays. Nobody works on Sundays. Full time staff must work 8 hours a day, five days a week. Part time staff work 4 hours a day, 5 days a week. Nobody is allowed to work overtime. All employees receive the same hourly rate. What is the number of part time and full time employees that fully staffs the operation with the smallest total labor cost?

"Find the retail cost of gasoline (per unit volume) in your area and find the cost of electricity for residential users in your area. (a) Compare the cost of energy (per MJ) from gasoline and from electricity (b) The efficiency of a gasoline automobile is about 20% and the efficiency of a battery electric vehicle is about 85%. Discuss the relative transportation costs for gasoline and electric vehicles."

a real sequence x_n is defined inductively by x₁ =1 and x_n+1 = sqrt(x_n +6) for every n belongs to N

a) prove by induction that x_n is increasing and x_n <3 for every n belongs to N

b) deduce that x_n converges and find its limit

1(a) If ut − kuxx = f, vt − kvxx = g, f ≤ g, and u ≤ v at x = 0, x = l and t = 0, prove that u ≤ v for 0 ≤ x ≤ l, 0 ≤ t < ∞.

(b) If vt − vxx ≥ cos x for −π/2 ≤ x ≤ π/2, 0 < t < ∞, and if v(−π/2, t) ≥ 0, v(π/2, t) ≥ 0 and v(x, 0) ≥ cos x, use part (a) to show that v(x, t) ≥ (1 − e −t ) cos x.