By Maria Jose Leon-Sotelo Esteban on Monday, August 13, 2001 - 06:15 am:
What is the value of cos(i), where i is the imaginary
unit?
Leon-Sotelo.
Thank you.
By Pooya Farshim on Monday, August 13, 2001 - 07:44 am:
It is cosh(1)=(exp(1)+exp(-1))/2, about 1.543:
From exp(iz)=cos(z)+isin(z) we get
cos(z)=(exp(iz)+exp(-iz))/2.
Pooya
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