Eulers FormulaYou are currentlybrowsing as guest. Click here to log in 

Complex analysis:
In the special case $\theta=\pi$ this reduces to Euler's Identity.
The functions cos and sin come originally from trigonometry, and it's just a little bit magical that they turn up in a purely algebraic context.
Interestingly, the formula also means that in some cases you can take logarithms of negative numbers. Specifically:
$\log(z)=\log(r.e^{i\theta})=\log(r)+i.\theta$ 
The log is not unique, though, because the same number z is represented by infinitely many values of $\theta.$
Last change to this page Full Page history Links to this page 
Edit this page (with sufficient authority) Change password 
Recent changes All pages Search 