function radioactive_decay ($half_life, $time
{
$lambda = log(2)/$half_life
return 100 - 100 * powexp(1), -1 * $lambda * $time);
}
function radioactive_decay ($half_life, $time
{
$lambda = log(2)/$half_life
return 100 - 100 * powexp(1), -1 * $lambda * $time);
}