2.4: Completed square and inverse sketch

0606/22/M/J/17 — Question 9 · 9 marks

A function ff is defined, for x32x \leqslant \tfrac{3}{2}, by f(x)=2x26x+5f(x) = 2x^{2} - 6x + 5.
(i)
Express f(x)f(x) in the form a(xb)2+ca(x - b)^{2} + c, where aa, bb and cc are constants.
[3]
(ii)
On the same axes, sketch the graphs of y=f(x)y = f(x) and y=f1(x)y = f^{-1}(x), showing the geometrical relationship between them.
[3]
(iii)
Using your answer from part (i), find an expression for f1(x)f^{-1}(x), stating its domain.
[3]