The profit from a grove of orange trees is given by P(x) = ax + bx2, where a,b
are constants and x is the number of orange trees per acre How many trees per
acre will maximise the profit (ii)
A ball, thrown into the air from a building 60 metres high, travels along a path
given by 
2
( )
60
x60
h x
x
=
+
−
, where x is the horizontal distance from the building
and h(x) is the height of the ball What is the maximum height the ball will
reach