Question

(b) The radioactive decay of a substance is given by the formula: m(t) = 500(0.92)' where m(t) is the mass (in grams) of the radioactive substance and t is its age in years. Write down the initial mass of the radioactive material. Write down the percentage by which the radioactivity decreases each year. Determine the mass of the substance after 50 years. Determine the least number of years it takes for the substance's mass to be less than one gram. Give your answer to the nearest year. (1) (2) (3) Given: f(x)==when x is rational but f(x)=x when x is irrational Evaluate f(4) + f(8).