(a)[2]
Express $3x^2 - 12x + 14$ in the form $3(x+a)^2 + b$, with $a$ and $b$ as the constants to determine.
(b)[1]
The function $f(x) = 3x^2 - 12x + 14$ is defined for $x \ge k$, where $k$ is constant. Determine the least value of $k$ for which $f^{-1}$ exists.
(c)[3]
For the remainder of this question, assume that $k$ takes the value found in part (b). Find an expression for $f^{-1}(x)$.
(d)[3]
Hence or otherwise, solve the equation $ff(x) = 29$.