5. My Notes Ask Your Teacher Q/1 points | Previous Answers SCalcET8 4.7.010. The rate (in mg carbon/m3/h) at which photosynthesis takes place for a species of phytoplankton is modeled by the function 2+1+1 where I is the light intensity (measured in thousands of foot-candles). For what light intensity is P a maximum? 1-1000 X thousand foot-candles Enhanced Feedback Please try again, keeping in mind that the critical points are zeroes of the derivative, points where the derivative is undefined, and limits of the domain. Use methods of calculus to find which point gives the maximum Need Help? Read It Talk to a Tutor