(i)[3]
Use the trapezium rule with $3$ intervals to estimate $\int_{\frac{\pi}{6}}^{\frac{2\pi}{3}} \cosec x\,dx$, and give your answer correct to $2$ decimal places.
(ii)[2]
Using a sketch of the graph of $y = \cosec x$, explain whether the trapezium rule gives an overestimate or an underestimate of the true value of the integral in part (i).