ช่วยแก้โจทย์หน่อยครับ

[ekkewbabay]

In a building the ventilation system operates when the concentration of carbon dioxide reaches a certain level.Suppose that when the ventilation system operates,the cubic feet of carbon dioxide,X,in an 8000 cu ft room depends on time t (in minutes) according to x=4.8+11.2(e^t/4)
a).Find the initial amount of carbon dioxide in the room,and find the concentration of carbon dioxide at this time.
b).How long does it take to have a concentration of 0.07% carbon dioxide?
c).The steady-state or equilibrium concentration is what would result if the ventilation system were left on indefinitely. By using large values for t ,determine the steady-state concentration.

[Panithi Vanasirikul]

e คืออะไรครับ อ่านเเล้วงง

[win1234]

$e$ คือจำนวนธรรมชาติครับ มีค่าเท่ากับ $\lim_{n \to \infty}(1+\frac{1}{n})^n$= 2.71828...