please provide explanation!

S is the distance (in ft) traveled in time t (in s) by a particle. Find the velocity and acceleration at the time t = 1 2. when St = . ( ) t+ 4 . each Velocity: Acceleration: The percent of concentration (or simply concentration) of a certain drug in the bloodstream 3: hours after the 2): x2 +49 . At what time is the concentration a maximum? drug is administered is given by K01) = Time: The position of a particle (in ft) is given by 8(t) = t3' 0t"' +9t . wheret is the time (in seconds) for which it has traveled. Find the time at which the velocity is a minimum. Show formulas used to determine this time. Time: The point of diminishing returns in economics is the point at which the rate of change of a function (revenue) quits increasing and begins decreasing. (Note: the rate of change of the function mg the function quits increasing and begins decreasing.) A company has up to $72,000 to spend in an advertising campaign. If it spends x dollars on advertising. its function for total sales will be approximately f(x) = 3.6M2 0.025:r" thousand dollars. Determine the point of diminishing retums. Point of diminishing returns: For the function f(x} = x5 + 5x\" 40x2 , determine the intervals over which it is . each Concave up: Concave down