# Thread: Find the equation for an exponential that passes through the following points:

1. ## Find the equation for an exponential that passes through the following points:

Find the equation for an exponential that passes through the following points:

(-1, 35/12) and (2, 126/25)

Having a lot of trouble on this, thanks for the help

2. ## Re: Find the equation for an exponential that passes through the following points:

What is the form you are to use, i.e., what are the two parameters? Is it:

$\displaystyle y(x)=y_0e^{rx}$ ?

3. ## Re: Find the equation for an exponential that passes through the following points:

Set up a system of equations using:
$\displaystyle y(x)=y_0b^{x}$
and solve

4. ## Re: Find the equation for an exponential that passes through the following points:

Okay, you have two parameters and two given points. We are told:

$\displaystyle y(-1)=\frac{35}{12}$

$\displaystyle y(2)=\frac{126}{25}$

Now using $\displaystyle y(x)=y_0b^x$, what is your system of equations?

5. ## Re: Find the equation for an exponential that passes through the following points:

I hope this helps:
$\displaystyle y(-1)=\frac{\35}{12}=ab^{-1}. \frac{35b}{12}=a$
Using a similar process for the second point allows you to solve for b, and consequently for a.