(i)[3]
Show that the area, $A$, of rectangle $OPQR$ is $A = 12x - \frac{3}{4}x^2$.
(ii)[4]
Given that $x$ is allowed to change, find the stationary value of $A$ and state its nature.
Mathematics 9709 · AS & A Level · Differentiation
Differentiation — practice question
The diagram shows $S$ at $(0, 12)$ and $T$ at $(16, 0)$. Point $Q$ lies on $ST$, between $S$ and $T$, with coordinates $(x, y)$. Points $P$ and $R$ are on the $x$-axis and $y$-axis respectively, and $OPQR$ forms a rectangle.