# Homework Help: Exponential growth

1. Feb 7, 2009

### intenzxboi

1. The problem statement, all variables and given/known data
Determine the period in which y = Cekt changes by a
factor of q.

I have no idea what it is asking.. find t when k=q????

2. Feb 7, 2009

### Hootenanny

Staff Emeritus
The question is asking to find the T (period) such that

$$y\left(t+T\right) = q\cdot y\left(t\right)$$

3. Feb 7, 2009

### intenzxboi

y(t + T) = C ek^(t+T) = C e^kt+kT = C e^kt · e^kT = e^kT y(t).

so q= e^kT ??

4. Feb 7, 2009

### Hootenanny

Staff Emeritus
I'm afraid that my browser cannot render the special character that you have typed (the coefficient of T).

5. Feb 7, 2009

### intenzxboi

I'm sorry huh???

6. Feb 7, 2009

### Hootenanny

Staff Emeritus
A special character 'placeholder' appears before each T in your expression, I thought that you may have typed a special character?

Last edited: Feb 7, 2009
7. Feb 7, 2009

### HallsofIvy

Yes, now solve for T.

8. Feb 7, 2009

### Hootenanny

Staff Emeritus
Thanks Halls. For some reason I was getting special characters inside intenzxboi's expressions.

9. Feb 8, 2009

### intenzxboi

Thanks guys.. without the help off all the tutors/mentor and other users i don't know how i will learn all this stuff