$3.[6$ points.$]$ Making $2-$D plots. Write a separate m$-$file for each part. Remember to print each plot to its separate PNG file and additionally write a text file with comments for the whole problem to explain briefly how you solved the problem.

$($a$)$ Plot each of the following functions over each specified domain. f $($x$)=2$ sin$($x$)+$ cos$($x$),$ x in $[2\backslash$pi $,2\backslash$pi $]$

g$($x$)=$ ex cos$($x$),$ x in $[0,2\backslash$pi $]$ h$($x$)=1,$ x in $[5,5]$

$($b$)$ Let

fk$($x$)=1,$ x in $[\backslash$pi $/2,\backslash$pi $/2].$ cos$2$ x$+$k$2$ sin$2$ x

Plot the function fk$($x$)$ for k $=2,3,$ and $4$ in the same graph. You will need to use hold on before you use plot and hold off after the final plot to ensure all lines show up in the axes. Add annotations to make the plot more effective.

$4.[4$ points.$]$ Reading Assignment. Remember to write a text file with comments for the whole problem to explain briefly what you did and what you learned.

Matlab offers extensive documentation through its Help facility.

$($a$)$ Follow the tutorial and look through the Get Started Guide to familiarize yourself with Matlab. Immediately, study the first five sections carefully: Desktop Basics, Matrices and Arrays, Array Indexing, Workspace Variables, Text and Characters, and Calling Functions. Then, before the next class, finish by looking through the remaining ones: $2-$D and $3-$D Plots, Programming and Scripts, and Help and Documentation.

$($b$)$ Follow the suggestion in the tutorial and look at the documentation, both from help and from doc, of some functions mentioned, starting with ls$,$ pwd$,$ cd$,$ etc., mathematical functions like factorial, sin$,$ etc., and plotting functions like plot, mesh, etc. The goal is not to understand the contents of the documentation fully, but to learn how to access it and what kind of information is there.$1+$x$2$

For each plot, make sure to add appropriate annotations to the plot to make it more effective. As a minimum, you need axes labels, a title, grid lines, and control the domain.