Consider an exponential decay function P(t) = P 0 e -t , and let T denote its time constant. Show that, at t = T,

Consider an exponential decay function P(t) = P₀e^-λt, and let T denote its time constant. Show that, at t = T, the function P(t) decays to about onethird of its initial size. Conclude that the time constant is always larger than the half-life.