For this problem, A is the variable for the amount of radioactive material, k is the growth constant (and assumed to be positive). The amount of radioactive material decreases at a rate proportional to the amount present. Write a differential equation to model the situation: Differential equation: dA/dt = -kA.
Find the formula for the half-life of the material: t(1/2) = (ln2)/k.
Note: You can earn partial credit on this problem.