- #1
contempquant
- 13
- 0
Homework Statement
Homework Equations
from the identities found on the internet:
[tex]cos(x)=\frac{(e^{ix}+e^{-ix})}{2}[/tex]
and
[tex]cosh(x)=\frac{(e^{x}+e^{-x})}{2}[/tex]
The Attempt at a Solution
Assuming for the definition of cosh(x), if we take x as being equal to (ix), then surely this shows that cosh(x)=cos(x)? Can someone explain why this is wrong please? because i can't see it