Jambmaths question:
Differentiate sin x – x cos x
Option A:
$x\cos x$
Option B:
$\sin x$
Option C:
$x\cos x$
Option D:
$x\sin x$
Jamb Maths Solution:
$\begin{align} & y=\sin x-x\cos x \\ & \frac{dy}{dx}=\cos x-\underbrace{\left[ x(-\sin x)+\cos x(1) \right]}_{product\text{ }rule\text{ }in\text{ }use} \\ & \frac{dy}{dx}=\cos x+x\sin x-\cos x \\ & \frac{dy}{dx}=x\sin x \\\end{align}$
Jamb Maths Topic:
Year of Exam: