$(10\%)$ Plotting.

Problem $2\mathrm{.}1.(5\%)$ Consider $75$ equally spaced values of $x$ in the range $-15x15.$ Plot the following

functions against $x$ :

$y(x)=-8x-x^{3}sin(x)-100$

$t(x)=co{s}^2(\frac{x}{4})$

Include grid lines, axis labels, and a title in each plot. Plots should be on separate graphs $($i$.$e$.,2$ graphs in total

for problem $2\mathrm{.}1).$

Hints: use the function "linspace$($start value, end value, # values$)"$ to generate vectors with equally spaced

values between a start value and an end value. Use the functions "xlabel", "ylabel", "title", "grid on$",$ and

"figure" to add the $x$ label of a graph, add the $y$ label of a graph, add the title of a graph, add grid lines on a

graph, and create a new window for a new graph, respectively.

Problem $2\mathrm{.}2.(5\%)$ Create a mesh using $120$ evenly spaced values in the interval $-5x5,$ and $60$ evenly

spaced values in the interval $-10y10.$ Plot surface graphs for the following functions:

$z(x,y)=\frac{x}{4}+\frac{y^2}{11}-20xy$

$v(x,y)=3si{n}^2(\frac{y}{2})co{s}^2(\frac{x}{4})$

Include grid lines, axis labels, and a title in each plot. Plots should be on separate graphs $($i$.$e$.,2$ graphs in total

for problem $2\mathrm{.}2).$

Hints: Use the functions "xlabel", "ylabel", "zlabel", "title", "grid on$",$ and "figure" to add the $x$ label of a

graph, add the $y$ label of a graph, add the $z$ label of graph, add the title of a graph, add grid lines on a graph,

and create a new window for a new graph, respectively.