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.
I know for the simplest TI-30, they have an INV button and for later models they have a 2ND function button, but here is my suggestion
.4
±
x
9
=
INV or 2ND
ln
=
x
7
you should get .191266..
Thank You!
To solve this problem using a TI-30 calculator, you can use the exponential function key (usually denoted as "e^x" on the calculator). Here are the steps to enter the expression and calculate the result:
1. Start by turning on the calculator.
2. Clear any previous calculations by pressing the "AC" or "C" button.
3. Enter the value of -0.4 multiplied by 9. To do this, press the following keys in sequence: "-","0",".","4","x","9".
4. Once you've entered -0.4 x 9, press the exponential function key. On a TI-30 calculator, the exponential function key is "2nd" followed by the key with "e^x" or "ee" symbol (usually located on the same button as the "ln" or "log" function).
5. After pressing the exponential function key, enter the coefficient 7. To enter the coefficient, simply press "7".
6. Finally, press the "equals" (=) key to calculate the result.
The calculator will display the value of 7e^(-0.4 x 9) in scientific notation format. If you want to round the result to three decimal places as requested in the question, you can refer to the calculator's instructions on how to round a result.