1.63: Stationary point and small increments

0606/13/M/J/17 — Question 11 · 9 marks

A curve has the equation y=6x−xxy = 6x - x\sqrt{x}.
(i)
Find the coordinates of the stationary point of the curve.
[4]
(ii)
Determine the nature of this stationary point.
[2]
(iii)
Find the approximate change in yy when xx increases from 44 to 4+h4 + h, where hh is small.
[3]