(i)[2]
Find the value of $a$ in this case.
(ii)[3]
Show that, for this value of $a$, the equation $f(x) = 0$ has just one real root.
Mathematics 9709 · AS & A Level · Differentiation
Differentiation — practice question
The polynomial $f(x)$ is given by $f(x) = x^3 + ax^2 - ax + 14$, with $a$ a constant. It is stated that $(x + 2)$ is a factor of $f(x)$.
Worked solution & mark scheme
This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Substitute $-2$ into the equation and set the result to zero, or divide by $x+2$ and set the remainder to zero, or use synthetic division” …
- Full mark scheme, point by point
- Step-by-step worked solution
- Write your answer & get it marked instantly by AI