Question

Differentiate w.r.to $t$
$y=\cos (5-3t),\frac{dy}{dt}=$

• A. $5\sin (5-3t)$
• B. $3\sin (5-3t)$
• C. $-5\sin (5-3t)$
• D. $-3\sin (5-3t)$

Answer 1

The correct option is B $3\sin (5-3t)$

$y=\cos (5-3t)$

differentiating on both sides w.r.t $x$

$\frac{dy}{dt}=-\sin (5-3t)\frac{d(5-3t)}{dt}$

$\therefore \frac{dy}{dt}=3\sin (5-3t)$