Answer
$-0.60$
Work Step by Step
Apply the chain rule:
$\dfrac{dP}{dt}=(\dfrac{\partial P}{\partial L})(\dfrac{dL}{ dt})+(\dfrac{\partial P}{\partial k})(\dfrac{dK}{dt})$
or, $=(-1.911)k^{0.35}L^{-0.35}+0.25725 L^{0.65}K^{-0.65}$
or, $=-1.203233025+0.607401286$
or, $\approx -0.595831738$
or, $ \approx -0.60$
