Problem Statement: EE Board March 1998
Given the following series:
Sin x = x – (x3/3!) + (x5/5!) + …..
Cos x = 1 – (x2/2!) + (x4/4!) + …..
ex = 1 + x + (x2/2!) + (x3/3!) + ….
What relation can you draw from these series?
- A. ex = cos x + sin x
- B. eix = cos x + isin x
- C. eix = icos x + sin x
- D. iex = icos x + isin x
The equivalent relation of the given series is B. eix = cos x + isin x.Solution: