Denise G. answered 04/02/20
Algebra, College Algebra, Prealgebra, Precalculus, GED, ASVAB Tutor
The general equation for exponential growth is
A=Ao(ekt)
A = Final amount
Ao = Initial amount
k = growth constant
t = time
Plug in the variables known
1800=1000(ek(1)) We can solve this for k to find the growth constant. Divide both sides of the equation by 1000
1.8=ek Take the ln of both sides
ln(1.8)=ln(ek) The exponent comes to the front
ln(1.8)=(k)(ln(e) ln e = 1
ln(1.8)=k
k=0.5878
Now, can use k to solve for t in the second part of this problem. Plug in the values you know. You will solve for t.
10000=1000(e0.5878t) Divide both sides of the equation by 1000
10=(e0.5878t) Take the ln of both sides
ln(10)=ln(e0.5878t) The exponent comes to the front
ln(10)=(0.5878t) ln(e) ln e = 1
ln(10)=0.5878t Divide both sides by 0.5878 and simplify
t=3.9 days