\(f(x) = -2x^3 - x^2 + 4x + 3\)
- Use the factor theorem to show that \((3 - 2x)\) is a factor of \(f(x)\). [2]
- Hence show that \(f(x)\) can be written in the form \(f(x) = (3 - 2x)(x + a)^2\) where \(a\) is an integer to be found. [4]
\includegraphics{figure_3}
Figure 3 shows a sketch of part of the curve with equation \(y = f(x)\).
- Use your answer to part (b), and the sketch, to deduce the values of \(x\) for which
- \(f(x) \leq 0\)
- \(f'(\frac{x}{2}) = 0\)
[3]