The velocity, v, with which air comes out depends on the radius, r, of your windpipe. If R is the normal (rest) radius of your windpipe, then for r R, the velocity is given by v = a(R – r)r2 , where a is a positive constant. What value of r maximizes the velocity? 4. The temperature change, T , in a patient generated by a dose, D of a particular drug is given by T = where C is a positive constant. (a) What dose maximizes the temperature change? DT (b) The sensitivity of the body, at dosage D, to the drug is defined to be . What dosage maximizes dD sensitivity?