A curve C C\,C is defined by the function
y=15+12x−12x2−13x3 y = 15 + 12x - \frac{1}{2}x^2 - \frac{1}{3}x^3 y=15+12x−21x2−31x3Using calculus, determine the xxx-coordinates of the stationary points of CCC.
Justify, by using the second derivative, the nature of each of these stationary points.
115 exam-style questions on CCEA A Level Maths 1.6 Differentiation, covering 1.6.1 Differentiation, 1.6.2 Differentiation, 1.6.3 Differentiation, 1.6.4 Differentiation, 1.6.5 Differentiation, 1.6.6 Differentiation, and 1.6.7 Differentiation. Each one has a worked solution and a mark scheme showing where the marks go.