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

• Nov 25th 2012, 09:17 PM
Dima110
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 :)
• Nov 25th 2012, 09:43 PM
MarkFL
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:

$\displaystyle y(x)=y_0e^{rx}$ ?
• Nov 26th 2012, 02:22 AM
divans
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
• Nov 26th 2012, 02:31 AM
MarkFL
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?
• Nov 27th 2012, 11:30 AM
divans
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.