Answer
$-2cos(cos(2t-5))(sin(2t-5))$
Work Step by Step
Put 2t-5=u and cos u=v.
Then, y= sin v.
According to the chain rule,
$\frac{dy}{dt}= \frac{dy}{dv}\times\frac{dv}{du}\times\frac{du}{dt}$
$= cos v\times-sin u\times2$.
Substituting values,
$\frac{dy}{dt}= cos(cos(2t-5))\times-sin(2t-5)\times2$
=$-2cos(cos(2t-5))(sin(2t-5))$
