Difference between revisions of "Exponential function"

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Exponential functions are in one of three forms.  
 
Exponential functions are in one of three forms.  
:<math>f\left( x \right) = ab^x </math>
+
:<math>f\left( x \right) = ab^x </math>, where ''b'' is the % change written in decimals
 
:<math>f\left( x \right) = ae^k </math>, where ''e'' is the irrational constant ''2.71828182846....''
 
:<math>f\left( x \right) = ae^k </math>, where ''e'' is the irrational constant ''2.71828182846....''
 
:<math>f\left( x \right) = a\left( {{1 \over 2}} \right)^{{x \over h}}  
 
:<math>f\left( x \right) = a\left( {{1 \over 2}} \right)^{{x \over h}}  

Revision as of 06:20, 10 November 2006

The exponential function is the function $f(x) = e^x$, exponentiation by e. It is a very important function in analysis, both real and complex.


Exponential functions are functions that grows or decays at a constant percent rate. Exponential functions that result in an increase of y is called an exponential growth. Exponential functions that result in an decrease of y is called an exponential decay.


An exponential growth graph looks like: 2 power x growth.jpg

An exponential decay graph looks like:

05 power x decay.jpg


Exponential functions are in one of three forms.

$f\left( x \right) = ab^x$, where b is the % change written in decimals
$f\left( x \right) = ae^k$, where e is the irrational constant 2.71828182846....
$f\left( x \right) = a\left( {{1 \over 2}} \right)^{{x \over h}}$ or $f\left( x \right) = a\left( 2 \right)^{{x \over d}}$, where h is the half-life (for decay), or d is the doubling time (for growth).


Whether an exponential function shows growth or decay depends upon the value of its b value.

If $b > 1$, then the funciton will show growth.
If $0 < b < 1$, then the function will show decay.



this page is still under construction...more to come very soon