Posted by **Hannah** on Wednesday, November 3, 2010 at 10:04pm.

The function D(h)=7e^-0.4(h) can be used to determine the milligrams D of a certain drug in a patient's bloodstream h hours after the drug has been given. How many milligrams will be present after 9 hours. Round three decimal places.

so 7e^(-0.4 x 9) = .191

To get this answer I used a TI-83 calculator. My question is how do I enter this in a TI-30 calculator.? In my math class we are not allowed to use the TI-83.