From the graph, it can be observed that speed of Diego increases from 10 km per sec to 12 km per sec for the distance from 5 km to 6km and after that distance from 6 km to 8 km the speed decreases from 12 km per sec to 10 km per second.
After 8 km to 9 km the speed increases from 10 km per sec to 11 km per sec.
After 9 km to 10 km the speed remain constant to 11 km per sec.
Thus Diego's speed can be expreesed as,
For 4 km to 6 km speed increase from 10 km per sec to 12 km per sec.
For 6 km to 8 km the speed decreases from 12 km per sec to 10 km per sec.
For 8 km to 9 km the speed increases from 10 km per sec to 11 km per sec.
For 9 km to 10 km the speed remain constant to 11 km per sec.
