# 2013F002/HW8s

### From CDS 130

Sample Quiz

Covering Modeling_Introduction, Mathematical_Models, and ODEs

# 1. Mathematical Representation

Write a mathematical representation of the following. Use the symbol `T`

to represent temperature.

The temperature of an object doubles every minute.

What is the formula that expresses the written portion above? If the initial temperature of the object was 100 degrees, what is its temperature after 5 minutes?

# 2. Iteration

Suppose that you deposit $19 in your account at the end of each year and that you started with $100 at the start of the first year. At the start of the each year, the bank gives you 10% interest on the money that was in your account the previous year.

What is the computational formula you would use to calculate the balance?

Does this program compute the balances correctly? Show your work.

B(1) = 119; for i = 1:4 B(i+1) = B(i)*1.1 + 19; end B

What is your balance at the end of the fourth year?