The amounts A, B, and C, in grams, are decaying exponentially according to the functions below. Which amount will decay to 4 grams fastest?

A(t) = 8 e-0.1386t

B(t) = 10 e-0.2t

C(t) = 9 e-0.3t

Okay i just need someone to show me how to do this please dont give me the answer i wanna find it on my own that way i know how to do it in the future. thanks

Question

The amounts A, B, and C, in grams, are decaying exponentially according to the functions below. Which amount will decay to 4 grams fastest?

A(t) = 8  e-0.1386t

B(t) = 10  e-0.2t

C(t) = 9  e-0.3t

Okay i just need someone to show me how to do this please dont give me the answer i wanna find it on my own that way i know how to do it in the future. thanks

anonymous · Answer

you want to know when the amount will be 4 grams to put 4 on the left hand side (i.e. replace A(t), B(t) and C(t) with 4)  then solve for t

anonymous · Answer

4=8e^(-.1386t)

anonymous · Answer

okay thank you that will help me alot!!