$($c$)$ Declare that $$ and $t$ are symbolic variables and enter the values of the constants,

$g=9\mathrm{.}8m{s}^{-2},l=1m,c=0\mathrm{.}5m{s}^{-1}.$

$($d$)$ To solve second order equations, it's easiest to name the first and second deriva$-$

tives, eg enter Dtheta $=$ diff$($theta$),$ and something similar for the second

derivative, D$2$theta.

$($e$)$ Use dsolve to solve the equation, eg angle $=$ dsolve$($D$2$theta$==...).$ As$-$

sume the pendulum is held so that $=\frac{}{4}$ to begin with, and it's held still

and then let go so that the initial velocity is zero, ${}^{\text{'}}(0)=0.$

$($f$)$ Plot the solution using ezplot for $0t10.$