Let h(t)=t2+1t for t>0.
a. Compute h′(t). Show all algebraic steps in your work.
b. Evaluate h′(t) at t=3, giving your answer in simplest exact form.
c. Suppose h(t) models the concentration (in milligrams per liter) of a substance in a reactor at time t hours. Interpret the meaning of the numerical value obtained in part (b) within this context, including appropriate units.