$($a$)$ Modify the function ex$\_$with $2$eqs to solve the IVP $(4)$ for $0t50$ using the MATLAB routine ode$45.$ Call the new function LAB$04$ex$1.$

Let $t,Y($note the upper case $Y)$ be the output of ode$45$ and $y$ and $v$ the unknown functions. Use the following commands to define the ODE:

function $dYdt=f(t,Y)$

$y=Y(1)$;$v=Y(2)$;

$dYdt=[v$;$2**sin(t)-6**v-7**y]$;

Plot $y(t)$ and $v(t)$ in the same window $($do not use subplot$),$ and the phase plot showing $v$ vs $y$ in a separate window.

Add a legend to the first plot. $($Note: to display $v(t)=y^{\text{'}}(t),$ use $\text{'}v(t)=y\text{'}\text{'}($:$(t{)}^{\text{'}}$