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.

The function D(h) =7e^-0.4h can be used to determine the milligram 12 hours?

To solve this equation using a TI-30 calculator, you can follow these steps:

1. Turn on the calculator by pressing the "ON" button.
2. Press the "2nd" button, then the "LN" button to access the natural logarithm function.
3. Enter the value of the exponent, in this case, -0.4 multiplied by 9. To do this, press the "(-)" button, followed by "0.4", "*", and finally "9".
4. Press the "=" button to evaluate the expression. This will give you the value of -3.6.
5. Press the "2nd" button, then press the "e^x" button to access the exponential function.
6. Input the value of -3.6 by pressing the "(-)" button followed by "3", ".", and "6".
7. Press the "=" button to evaluate the expression. You should get approximately 0.026, rounded to three decimal places.

Therefore, using a TI-30 calculator, you can determine that there will be approximately 0.026 milligrams of the drug present in the patient's bloodstream after 9 hours.

To calculate this on a TI-30 calculator, you can follow these steps:

1. Start by entering the base of the natural logarithm, "e". On the TI-30 calculator, press the "2nd" button followed by the "LN" button, which corresponds to the natural logarithm.

2. Multiply the result of step 1 (-0.4) by 9. Enter -0.4 by pressing the "-" button, followed by the "0.4" button, and then multiply it by 9 using the "×" button.

3. Raise "e" to the power obtained in step 2. To do this, press the "^" button (located above the "7" key), and then enter the result from step 2.

4. Multiply the result of step 3 by 7. Enter 7, followed by the "×" button, and then the result from step 3.

5. Finally, press the "=" button to calculate the result.

The result displayed on the screen will be the number of milligrams present after 9 hours. Round this value to three decimal places according to the problem's instructions.