Sunday, 25 October 2015

exponentiation - What do we actually mean by raising some number to an imaginary power?

It seems quite intuitive when we say that some number a is raised to a power b where aC and bZ and can be expressed as
ab=a×a×a...(b times)


Extending the argument such that bR then if b is rational, it can be expressed in the form pq such that p,qZ and q0 and ab is defined as
apq=qap

If b is irrational then ab is a transcendental number as stated by Gelfond- Schneider theorem (a and b are algebraic numbers). Agreed.




Now, here is the problem: What happens when b is an imaginary number? What is an intuitive idea behind saying iθ times in the expression (I may be wrong in saying that)
eiθ=e×e×e...(iθ times)=cosθ+isinθ


Yes, thats the Euler's theorem.

No comments:

Post a Comment

real analysis - How to find limhrightarrow0fracsin(ha)h

How to find limh0sin(ha)h without lhopital rule? I know when I use lhopital I easy get $$ \lim_{h\rightarrow 0}...