- What do
`1:10`

,`1:2:10`

`100:-25:0`

do? Think, then check. - Let
`x = [2 5 1 6]`

. What will`x(3)`

,`x([1 2])`

,`x([1:end])`

,`x(end:-1:1)`

,`x(:)`

,`x([1 1 1 1])`

do? Think, guess, discuss with a friend, and finally, verify. - When creating a matrix, a space or a comma (
`,`

) are the separator between*columns*, while a semicolon (`;`

) separate between*rows*. Figure out how to create the following matrices: \(\begin{pmatrix} 1& 2& 3\\ 4&5&6 \end{pmatrix}\), \(\begin{pmatrix} 1& 0 &1 \\ 0& 1& 0 \end{pmatrix}\) - You can
*nest*matrix construction so that`[ 6 (1:5) 7 ]`

makes sense (what does it result in?) Similarly you can create a matrix by stacking column vectors next to each other (using a space or a comma) or row vectors on top of each other (using a semicolon). Create the following matrix using a relatively short line of code:\begin{equation} \begin{pmatrix} 1 &2&3&4&5&6&7&8&9&10\\ 1&4&9&16&25&36&49&64&81&100\\ 2&4&8&16&32&64&128&256&512&1024 \end{pmatrix} \end{equation}Can you now easily make the first list go up to 100 (and the others follow suit)? If not, solve the problem again so that you can do it.

The `plot`

command plots a list of points given as two vectors, \(X\) and \(Y\) of their x- and y- coordinates, respectively. The default behaviour is that no mark is placed on the points, and the points are joined by a straight line. So if we want to plot a parabola \(y=x^2\) for \(x\in[-1,1]\) we can write:

| Graphing a simple function, y=x^2. |

We could make that line green by adding a third input:

| Stylizing the graphs with colors and line markers. |

The resulting plot need not be a function in the mathematical sense of the word:

| Graphing a non-function in MATLAB®. |

**Exercise 10.** *Read the helpfile on *`plot`

* by typing *`help plot`

* and figure out how to do the following:*

* *

*Plot*only*the points and not the lines**Plot the parabola sideways (the result is not a function)**Plot using a red, dashed line and stars at each point**Make the plot with less points so that you can see that the lines between the points are straight**Plot the function \(\sin x\) vs. \(x\), for \(x\in [0,6\pi]\)**Figure out how to plot two functions with the same*`plot`

*command, and plot \(\sin x\) and \(\cos x\) vs. \(x\).*