A biological culture's sensitivity to a stimulant, SSS, is modeled as a function of the concentration ccc (in mmol/L) by the formula:
S=(12c4−8c)9 S = \left( \frac{1}{2}c^4 - \frac{8}{c} \right)^9 S=(21c4−c8)9Use the chain rule to find an expression for the rate of change of sensitivity with respect to concentration, dSdc\frac{dS}{dc}dcdS.