$```$

a $=???$; b $=???$; y$\backslash$theta $=???$;

f $=$ @$($t$,$y$)???$;

$[$texact$,$ yexact$]=$ ode$45($f$,[$a b$],$ y$0)$;

$\%$ we will compare our approximation to MATLAB's fine approximation

$???$;

for h $=[1/2,1/8,1/32]$

$???$;

$???$;

y $=???$;

for i $=1$:N

$???$;

$???$;

$???$;

$???$;

y$($i$+1)=???$;

end

figure$($counter$)$

plot$($t$,$y$,\text{'}$r$*\text{'},$texact,yexact,$\text{'}$b$\text{'})$;

counter $=$ counter $+1$;

end

$```$