# How can I find the equation of an exponential equation given a set of points?

I know the equation that fits the given points is exponential. What is the best way to find the equation?

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Perhaps you'll want to consider an exponential regression. Here is an online tool (very easy to use).

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Quoting from that link: "This page allows you to work out exponential regressions, also known as exponential least squares fittings. For the relation between two variables, it finds the exponential function that best fits a given set of data points". –  Shai Covo Jun 28 '11 at 19:38

If you have an equation of the form $y=ae^{bx}$, you can think of it similarly as the points $(x,\log{(a)}+bx)$ and run a linear regression on this to find the choices of $(a,b)$.

Edit: You're running a linear regression on $(x, \log{(y)})$, which there are many methods. Once you get your $\log{(y)}$ values, just exponentiate them.

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This is a simple method, but not recommended for serious use. For an example of what can go wrong, see mathworks.com/products/statistics/demos.html?file=/products/…. –  Hans Lundmark Jun 29 '11 at 14:47