SOLUTION: Samantha invested $4,000 at an interest rate of 4% compounded continuously. The function represents the total amount of the investment after t years. A(t)=4,000e^(0.04t) Whic

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: Samantha invested $4,000 at an interest rate of 4% compounded continuously. The function represents the total amount of the investment after t years. A(t)=4,000e^(0.04t) Whic      Log On


   

Question 1108964: Samantha invested $4,000 at an interest rate of 4% compounded continuously. The function represents the total amount of the investment after t years.
A(t)=4,000e^(0.04t)
Which expression represents the number of years, t, required for her investment to triple?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+A%28t%29+=+4000%2Ae%5E%28+.04t+%29+
After +t+ years, the investment triples
+A%28t%29+=+3%2A4000+
+A%28t%29+=+12000+
+12000+=+4000%2Ae%5E%28+.04t+%29+
+3+=+e%5E%28+.04t+%29+
Take the natural log of both sides
+ln%283%29+=+.04t+ ( they may just want this )
+1.0986+=+.04t+
+t+=+1.0986+%2F+.04+
+t+=+27.4653+%7D+ yrs