Answer:
a. 8.1 milligrams
b. 40.07 hours
c. 8.859 milligrams
Explanation:
If a person takes a prescribed dose of 10 milligrams of Valium, the amount of Valium in that person's bloodstream at any time can be modeled by

Where A(t) = amount of Valium remaining in the blood after t hours
t = time or duration after the drug is taken
a. we have to calculate the amount of drug remaining in the bloodstream after 12 hours


= 10×0.81253
= 8.1 milligrams
b. In this part we have to calculate the time when A(t) = 5 milligrams


0.5 = 
Now we take natural log on both the sides of the equation.
ln(0.5) = ln(
-0.69314 = -0.0173t
t = 
t = 40.0658
≈ 40.07 hours
c. In this part we have to calculate the rate, by which amount of drug will decay in the bloodstream after 7 hours.


= 10×0.8859
= 8.859 milligrams
The guard cell is responsible for controlling the size of the stomata in leaves. These do so as a result of an interaction between potassium ions and water in and around the cells. When potassium ions accumulate inside the guard cells the water potential inside these cells is lower than that of the outside and as a result, water has to be taken in. This makes the guard cells turgid which in turn stretches them and results in the opening of the stomata. Meanwhile, when potassium ions accumulate outside the cell, the opposite scenario results. Water from inside the cell moves out, making the guard cells flaccid, thus causing these to cover (and effectively close) the stomata.
The Oligocene epoch follows the Eocene epoch.
The Paleogene Period began 56 million years ago and lasted for 23 million years can be divided into three periods: the Paleocene Epoch, the Eocene Epoch, and the Oligocene Epoch, all of which are then divided into their respective smaller eras.
Answer:
A. Live with little water needed