3.1
Question 1
Help gives detailed information about the funtion written after it, with additional sourcss for information.
helpwin lists topics for groups of functions.
doc displays online documentation in the Help browser inside matlab.

Question 2
ver gives detailed version description with package names and directories
version version gives version number only


3.2
Question 1
ans is used to display the answer of the most recent answer, and is variable created automatically when you specify no output argument

Question 2
semicolons are used to separate rows in an array creation command, or to suppress the output display of a line of code.

Question 3
yes, variables are case sensetive.

Question 4
These are functions, not variables.
It's possible to overwrite them, and they will turn into variables.
to undo it, you need to use the clear function.

Question 5
the semi colon in this function seperates rows in the array (matrix)

Question 6
A = [0:3.14/4:3.14]

Question 7
A=[1:3 ; 4:6 ; 7:9]

Question 8
rand(M,N) uniformly distributed random numbers and arrays in an m-by-n matrix of random entries
randn(M,N) Normally distributes random numbers and arrays in an m-by-n matrix of random entries

Question 9
returns the sizes of each dimension of an array in a vector.

Question 10
displays value of variable

Question 11
because X is 4x2, Y is 3x4

Question 12
puts elements on the main diagonal only

Question 13
sums diagonal elements

Question 14
a = sum(diag(A));

Question 15
displays cell array contents

Question 16
indicates nonexecutable text within the body of a program

Question 17
Curly braces encase the answer in a cell

Question 18
gets names of fields

Question 19
determines whether input is a structured array

Question 20
rmfield

3.3
Question 1
The %{ and %} symbols enclose a block of comments that extend beyond one line
% is a one line comment

Question 2
the gamma increased

Question 3
The picture gets brighter

Question 4
cellmode has functions that allow you to break your scripts into smaller chunks that can be run individually

Question 5
help is created by inserting comments at the beginning of your program. If your program includes a function, type the help text below the function definition line

Question 6
Elapsed time is 0.043596 seconds.
Elapsed time is 0.0402439 seconds.
0.003 faster?

Question 7
.^ is element-wise power
^ is matrix power

Question 8
Elapsed time is 0.00017786 seconds.
Much faster

Question 9
i=0;
t=0;
while t < 3.14*2
    t = t+3.14/4;
    i=i+1
    x(i) =sin(t)
end