Assume that the certain number of bacteria R(t) (in millions) present in a certain culture at time t (in hours) is given by R(t)=t^2(t-18)+96t+1000 a) In which time interval will the graph of R...

Assume that the certain number of bacteria R(t) (in millions) present in a certain culture at time t (in hours) is given by R(t)=t^2(t-18)+96t+1000

a) In which time interval will the graph of R concave down?

b) At which time will the number reach relative extrema? Use first and second derivative test

c) Sketch the graph of the number R(t)