1 h05 CS8 W19
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# h05: Perkovic 3.3-3.5 (Functions)

true Thu 01/24 02:00PM Wed 01/30 09:00AM

You may collaborate on this homework with AT MOST one person, an optional "homework buddy".

MAY ONLY BE TURNED IN IN THE LECTURE/LAB LISTED ABOVE AS THE DUE DATE,
OR IF APPLICABLE, SUBMITTED ON GRADESCOPE. There is NO MAKEUP for missed assignments;
in place of that, we drop the lowest scores (if you have zeros, those are the lowest scores.)

1. (10 pts) Please fill in the information at the top of this homework sheet, including your name and umail address. If the other two items apply, please fill them in as well. Please do this every single time you submit homework for this class. It is important to fill in both name and umail every time, since handwriting is sometimes difficult to decipher. Having both helps us ensure you get credit for your work.

DO NOT staple, paper clip, spit-fold-and-tear, or do ANYTHING that would make it difficult to automatically feed your paper through a scanner.

2. (20 pts) Page 68 lists this Python function definition that corresponds to the mathematical function `f(x) = x^2 + 1`

Note that we can also write this more simply without the `res` variable, saving a line of code.

Which version is better? That’s a matter of programming style. Often, but not always, writing in fewer lines of code is preferred. With experience, you’ll gain a sense of when to do one vs. the other. For this problem, it is up to you which option to use.

In the space below, please write a function definition for the mathematical function `g(x) = 2x^2 - 3x + 4`

3. The following is a function definition. Note that `def` is an abbreviation for definition: Contrast this with a function call such as ` f(3)`, `f(2 + 2)`, or `f(0.5)`. Those evaluate to `10`, `17`, and `1.25` respectively. Each of the problems below shows a function definition at left, then several function calls at right. For each function call, write what the function call evaluates to.
1. ``````def foo(x):
return 1 + x * 2
``````
pts function call write result here
(5 pts) `foo(3)`
(5 pts) `foo(-1)`
2. ``````def bar(s):
return s[1:3]
``````
pts function call write result here
(5 pts) `bar("blue")`
(5 pts) `bar("green")`
3. ``````def blerg(thing):
return thing[-1]
``````
pts function call write result here
(5 pts) `blerg("blue")`
(5 pts) `blerg([1,2,3])`
(5 pts) `blerg(["UCSB","Stanford","UCLA"])`
4. ``````def fleek(a,b):
return 2 * min(a,b)
``````
pts function call write result here
(5 pts) `fleek(3,5)`
(5 pts) `fleek(7,1)`
(5 pts) `fleek("UCSB","UCLA")`
4. (10 pts) According to Chapter 3, what is a docstring?
5. (10 pts) Add an appropriate docstring to the Python function below that converts inches to centimeters.

``````
def in2cm(inches):

return inches * 2.54

``````