A drug is injected into a patient's bloodstream. The concentration of the drug in the bloodstream t hours after the drug is injected is modeled by the formula C(t)= .12t/(t^2+t+1) miligrams per cubic centimeter. Estimate the change in concentration over the time period from 30 to 35 minutes after injection

So i took the derivative got ((t^2+t+1)(.12)-(2t+1)(.12t))/(t^2+t+1)^2

Plugged in .5 into the derivative and multiplied that by 5/60 (5minutes change in time) ended up with .00244898 and webwork says I'm wrong.

Anyone know what I did wrong?

Question

A drug is injected into a patient's bloodstream. The concentration of the drug in the bloodstream t hours after the drug is injected is modeled by the formula C(t)= .12t/(t^2+t+1) miligrams per cubic centimeter. Estimate the change in concentration over the time period from 30 to 35 minutes after injection

So i took the derivative got ((t^2+t+1)(.12)-(2t+1)(.12t))/(t^2+t+1)^2

Plugged in .5 into the derivative and multiplied that by 5/60 (5minutes change in time) ended up with .00244898 and webwork says I'm wrong.

Anyone know what I did wrong?