Mathematics

Problem

Identify the differential equation that describes exponential decay of a quantity

Q

with respect to time

t

. a)

\dfrac{dQ}{dt}=0.4\,Q

\dfrac{dQ}{dt}=-0.4\,Q^{2}

\dfrac{dQ}{dt}=-0.4\,Q

\dfrac{dQ}{dt}=\dfrac{Q}{0.4}