Complex Numbers And Quadratic Equations question 301
Question: The imaginary part of $ \cosh (\alpha +i\beta ) $ is [RPET 2000]
Options:
A) $ \cosh \alpha \cos \beta $
B) $ \sinh \alpha \sin \beta $
C) $ \cos \alpha \cosh \beta $
D) $ \cos \alpha \cos \beta $
Show Answer
Answer:
Correct Answer: B
Solution:
$ \cosh (\alpha +i\beta ) $ $ =\cosh \alpha \cosh (i\beta )+\sinh \alpha \sinh (i\beta ) $ Imaginary part $ =\sinh \alpha \sin \beta $ .
BETA
