4. (a) Sketch the graph of \(y = \frac { 1 } { x } , x > 0\)
The table below shows corresponding values of \(x\) and \(y\) for \(y = \frac { 1 } { x }\), with the values for \(y\) rounded to 3 decimal places where necessary.
| \(x\) | 1 | 1.5 | 2 | 2.5 | 3 |
| \(y\) | 1 | 0.667 | 0.5 | 0.4 | 0.333 |
(b) Use the trapezium rule with all the values of \(y\) from the table to find an approximate value, to 2 decimal places, for \(\int _ { 1 } ^ { 3 } \frac { 1 } { x } \mathrm {~d} x\)