Mathematics 9709 · AS & A Level · Differentiation

Differentiation — practice question

The function $f$ is specified for $x > \frac{1}{2}$, and its derivative is $f'(x) = 3\sqrt{2x - 1} - 6$.

(i)[4]

Determine the values of $x$ for which $f$ is decreasing.

(ii)[4]

You are now told that $f(1) = -3$. Determine $f(x)$.

Worked solution & mark scheme

This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Work out the inequality $(2x-1)^2<3(2x-1)^2<6$” …