#### Answer

$10t\sin t+5t^{2}\cos t$

#### Work Step by Step

$\dfrac {d}{dt}\left( 5t^{2}\sin t\right) =\left( \dfrac {d}{dt}\left( 5t^{2}\right) \right) \times \sin t+\left( \dfrac {d}{dt}\left( \sin t\right) \right) \times 5t^{2}=10t\sin t+5t^{2}\cos t$