5 The outline of a building can be modelled
by the function h=2x-0.1x² where his the
height of the building and x the horizontal
distance from the start of the building.
An observer stands at the point A. The angle
of elevation from his position to the highest
point he can see on the building is 45°.
Calculate the height above the ground
of the highest point he can see on the
building.